# [seqfan] Re: Which sequence is it

Richard Mathar mathar at strw.leidenuniv.nl
Sat Feb 11 22:52:38 CET 2012

jwn> Date: Sat, 11 Feb 2012 13:06:02 -0800 (PST)
jwn> From: "John W. Nicholson"
jwn> Subject: Re: Which sequence is it
jwn> To: Richard Mathar
jwn>
jwn> ."=A0=0A=0ASo, on a compound table like the above how is it placed in a sin=
jwn> gle sequence or should it be place as other sequences? How is the b-file ma=
jwn> de, designed for a compound table?=0A=0AI do not have Maxima or=A0Maple. Ho=

The two ways of choosing the primes or the x as rows or columns differ
in taking the transpose of the array. The way that I oriented them is
the natural one, because this would be stored by deleting the zeros,
and reading everything line by line:

1
1 1
2 1
2 1 1
2 1 1
2 1 1 1
3 1 1 1
3 2 1 1
3 2 1 1
3 2 1 1 1
3 2 1 1 1
3 2 1 1 1 1
3 2 1 1 1 1
3 2 1 1 1 1
4 2 1 1 1 1
4 2 1 1 1 1 1
4 2 1 1 1 1 1
is stored as the sequence
1 1 1 2 1 2 1 1 2 1 1 2 1 1 1 3 1 1 1 3 2 1 1 3 2 1 1 3 2 1 1 1 3 2 1 1 1 3 2 1 1 1 1 3 2 1 1 1 1 3 2 1 1 1 1 4 2 1 1 1 1 4 2 1 1 1 1 1 4 2 1 1 1 1 1 ...
with the keyword "tabf" (meaning that it's an irregular table because
the row lengths don't grow uniformly) on a per row basis.

Storing the other (transposed) way would mean to start each line with
a flexible number of zeros, which is usually an "obfuscating" feature because
it makes it more difficult to recognize the content.

Row length etc are simple formulas of some ceiling of logs etc,
and the few interesting columns deserve to be mentioned as references.
The third column with prime(3)=5, has already too many 1's to warrant a
special entry on its own, I think.

RJM