# An article in Frankfurter Allgemeine Zeitung

Reiner Martin reinermartin at nyc.rr.com
Tue Dec 18 05:22:36 CET 2001

```Since the automatic translation was a bit crude, I tried to translate this
article
myself as good as I could (my mother tongue is German). Here it is:

------------------------------------

Frankfurter Allgemeine Zeitung, May 9, 2001
Section: Nature and Science
Title: The Passion of a Integer Sequence Collector
Subtitle: Database with more than 61,000 entries / Wide interest with
mathematicians and amateurs

Some people collect stamps, other coins, calling cards, beer mats or
butterflies. There is hardly something which has not become the object of
the human passion to collect, even chamber pots and shoe laces have found
their devotees.  But the American mathematician Neil J. A. Sloane of the
AT&T Shannon Lab in Florham Park/New Jersey has probably chosen the most
unusual objects to collect.  He collects integer sequences.  Not any
arbitrary sequences however, but only such which consist of positive
integers, which have infinitely many elements, and which are build according
to a fixed rule.

Although Sloane is probably the only collector of integer sequences in the
world, his hobby is met with wide interest.  Thousands of scientists and
amateurs are helping him for many years now to continuously extend his
collection.  In December 1963 Sloane, who was at this time still a student
of Cornell University in Ithaca/New York, looked for information about a
certain sequence from graph theory.  But as hard as he tried, he could not
find anything about it in the relevant literature.  That annoyed him so much
that he began to collect sequences systematically.

Ten years later his collection contains over 2300 sequences from all areas
of mathematics, the natural sciences and even from puzzles.  He arranged
them lexically and published them as book with the title "A Handbook of
Integer Sequences."  The book became a success, and many people sent him new
sequences.  Neil Sloane continued to collect.  Together with Simon Plouffe
of the Université du Québec in Montréal he wrote in 1995 the "Encyclopedia
of Integer Sequences", which was with 5488 sequences more than twice as
large as his first collection.

In the same year Sloane created e-mail addresses with which one could make
automatic look-ups in his sequence database.  The book and the e-mail
addresses were a large success and led to an enormous wave of contributions
of new sequences.  One year later the collection had already increased to
16,000 sequences.  Then Sloane created also an Internet page for his
sequence database with special search functions
(www.research.att.com/~njas/sequences).  The interest among scientists and
also among amateurs is enormous.  Every day his collection is accessed about
2,500 times, which in the meantime contains over 61,000 sequences.

The collection of Sloane resembles a well sorted department store.  All
somehow conceivable sequences are to be found there.  Mathematical sequences
like those of the prime numbers (2, 3, 5, 7, 11 ...), the square numbers (0,
1, 4, 9, 16 ...) or the factorials (1, 1, 2, 6, 24 ...) are of course
chemistry like the number of different alkanes with n carbon atoms (1, 1, 1,
2, 3, 5 ...), or sequences from physics like the number of Feynman diagrams
of order 2n (1, 3, 18, 153, 1638...), as well as sequences from biology like
the possible secondary structures of a RNA molecule with n nucleotides (1,
1, 1, 2, 4, 8, 17 ...).

Additionally, the collection contains chess problems like the number of ways
of placing n queens on a chessboard with n by n squares in such a way that
they do not mutually attack themselves (1, 0, 0, 2, 10, 4, 40, 92 ...).  One
can also find curiosities like the sequence 0, 0, 0, 0, 4, 9, 5, 1, 1, 0, 55
...  It results from removing all letters except the number characters I, V,
X, L, C, D and M from the English numbers one, two, three, four, five, ...
The resulting words are then interpreted as Roman numbers.

The question "what is the next number?" of a given sequence, which is
popular in puzzle columns and intelligence tests, is easy to solve with
Sloanes collection.  For example, if one enters the sequence 3, 1, 4, 1, 5
into the search program, it offers thirty-five different possibilities to
continue the sequence.  One of the resulting sequences would be the one of
all integers, beginning with three, separated by ones.  Thus, the next
number would have to be one.  But it could also represent the decimals of
the number pi.  Then the next element would have to be nine.  Since 1998 the
American mathematician even publishes a special electronic magazine, the
"Journal of Integer Sequences", in contains exclusively articles on integer
sequences.

HEINRICH HEMME

Translated from the German by Reiner Martin

----- Original Message -----
From: "Antti Karttunen" <karttu at megabaud.fi>
To: <seqfan at ext.jussieu.fr>
Sent: Monday, December 17, 2001 1:00 PM
Subject: An article in Frankfurter Allgemeine Zeitung

>
> Jon Awbrey wrote:
>
>   ¤~~~~~~~~~¤~~~~~~~~~¤~~~~~~~~~¤~~~~~~~~~¤~~~~~~~~~¤
>
>   | Wollust ward dem Worm gegeben,
>   | Und der Cherub steht vor Gott!
>   |
>   | Friedrich von Schiller, Ode "An die Freude"
>
>   happy beethoven's birthday
>   and have a joyful new year!
>
>
> Warm Christmas greetings from Finland also!
>
>
> To delight your souls, I offer the article that appeared in
> Nr. 107 of Frankfurter Allgemeine Zeitung (09.05.2001),
> as faithfully translated to English by
>
> To see the original Deutsch version, read:
> http://www.megabaud.fi/~karttu/matikka/sloane.html
>
> and this "English" version is also available as:
> http://www.megabaud.fi/~karttu/matikka/sloane_eng.html
>
> (I fetched the article from the electronic archives of "Frankfurter
> Allgemeine"
> http://afaz.gbi.de/ (and choose "Suche", then enter "Sloane" to "Suche"
> field)
> and it cost me just 1,50 euros, that is, a bit over one dollar).
>
>
> Terveisin,
>
> Antti Karttunen
>
>
>
>    Nature and science Frankfurt general newspaper, 09,05,2001, NR. 107,
> S. N1
>
> __________________________________________________________________________
>
>    The passion of a number row collecting tank
>
>    Data base with more than 61,000 entries/interest with mathematicians
> and
>    laymen largely
>
>    Some humans collect stamps, other coins, calling cards, beer covers
>    or butterflies. There are hardly something, which did not become the
>    object of human collecting passion, even night pots and tying lacings
>    its lovers found. But for the probably most unusual collecting
> objects
>    the American mathematician Neil J. A has himself. Sloane of the AT&T
>    Shannon lab in Florham park/new jersey decided. He collects
> zahlenreihen.
>    However not any arbitrary, but only such, which consist many elements
> of
>    positive whole numbers, are infinitely have and in addition according
> to
>    a firm rule developed.
>
>    Although Sloane is probably the only collecting tank of zahlenreihen
> in
>    the world, its hobby encounters a broad interest. Thousands of
> scientists
>    and laymen help him for many years to constantly extend its
> collection.
>    In December 1963 Sloane, which was at this time still a student to
> the
>    Cornell University in Ithaca/New York, looked for information about a
>    certain zahlenreihe from the graph theory. But as it also strove
> itself,
>    it could find nothing over it in the relevant literature. That
> annoyed
>    it so much that he began to collect systematically zahlenreihen.
>
>    Later its collection over 2300 rows from all ranges of mathematics,
>    the natural sciences and even the mental exercise covered ten years.
>    It arranged it lexically and published it as book with the title
>    "A Handbook OF Integer Sequences". The book became a success, and
> many
>    humans sent to it thereupon new rows. Neil Sloane continued to
> collect.
>    it wrote 1995 together with Simon Plouffe of the Université you
> Québec in
>    Montréal the "Encyclopedia OF Integer Sequences", which was than
> twice
>    as large with 5488 zahlenreihen more like its first collection.
>
>    In the same year Sloane furnished E-Mail addresses, with which one
> could
>    make autopollings to its number row collection. The book and the
> E-Mail
>    addresses were a large success and led to an enormous tide of entries
>    with new rows. One year later had already increased the collection on
>    16,000 rows. Now Sloane arranged also its own InterNet side for its
>    number row collection with special search functions
>    ( http://www.research.att.com/~njas/sequences/ ).
>    The interest among scientists and also among laymen is enormous. Per
> day
>    for instance 2500mal his collection one accesses, which contains in
> the
>    meantime over 61,000 rows.
>
>    The collection of Sloane resembles a well sorted department store.
>    All only somehow conceivable zahlenreihen are to be found there.
>    Mathematical rows like those of the prime numbers (2, 3, 5, 7,
> 11...),
>    the quadratzahlen (0, 1, 4, 9, 16...) or the faculties (1, 1, 2, 6,
> 24...)
>    are naturally numerously represented. In addition, Neil Sloane seized
>    numbers of chemistry like the number of the different alkanes with
>    n carbon atoms (1, 1, 1, 2, 3, 5...) or numbers of physics like the
>    number of the Feynman graphs of the order 2n (1, 3, 18, 153, 1638...)
>    as well as numbers of biology like the possible secondary structures
>    of a RNA molecule with n nucleotides (1, 1, 1, 2, 4, 8, 17...).
>
>    In addition the collection contains chess problems like the number of
>    the possibilities of placing n ladies in such a way on a chessboard
>    with n fields that they do not threaten themselves mutually
>    (1, 0, 0, 2, 10, 4, 40, 92...). To find curiosities are additional
>    like the row 0, 0, 0, 0, 4, 9, 5, 1, 1, 0, 55... It results from the
>    fact that one paints three, four, from the English number words one,
>    two, five... all letters up to the number characters I, V, X, L, C, D
>    and M. The word remainders are then interpreted as Roman numbers.
>
>    In mystery columns and with intelligence tests question
>    "as, liked, is called the next number?" a given zahlenreihe is easy
>    with Sloanes collection to solve. If one enters the row 3, 1, 4, 1, 5
>    for example into the search program, it offers to thirty-five
> different
>    possibilities, how the row could continue. One of the resulting rows
>    would be from sequential whole numbers - beginning with the three -,
>    which are separate by ones in each case. The next number would have
>    to be thus unity. It could concern in addition, the decimal places of
> the
>    circle number of pi. Then the next element would have to be nine.
>    Since 1998 the American mathematician even gives a special electronic
>    magazine, which "journal OF Integer Sequences", out, in which
> excluding
>    articles over zahlenreihen appear.
>
>    HEINRICH RESTRAIN
>
>    All rights reserve. (C) F.A.Z . GmbH, Frankfurt/Main

```