[seqfan] Re: First fini sequence in the table?

Charles Greathouse charles.greathouse at case.edu
Sun Dec 15 19:31:38 CET 2013


It looks to me like the only finite sequences in the HIS were

%N A000797 Numbers that are not the sum of 4 tetrahedral numbers.
%N A000926 Euler's "numerus idoneus" (idoneal, or suitable, or convenient
numbers).
%N A001259 A sequence of sorted odd primes 3=p_1 < p_2 < ... < p_m such
that p_i-2 divides the product p_1*p_2*...*p_(i-1) of the earlier primes
and each prime factor of p_i-1 is a prime factor of twice the product.
%N A002205 The RAND Corporation list of a million random digits.
%N A003171 Discriminants of orders of imaginary quadratic fields with 1
class per genus (a finite sequence).

so that seems a 5-way tie for priority in 1973.

Charles Greathouse
Analyst/Programmer
Case Western Reserve University


On Sun, Dec 15, 2013 at 12:55 PM, <franktaw at netscape.net> wrote:

> By A-number, the first few fini sequences are A000053, A000054, A000797,
> A000926, A001049, A001219, A001228, A001259, A001272, and A001293.
>
> On another issue, there are sequences such as A164081 that are finite in
> the sense that from some point on they are zero. I think some such
> sequences are marked "fini", while others (like A164081) just have lots of
> zeros. We really ought to have a standard for this. (If we do decide these
> should be marked finite, A000004 would  of course be an exception.)
>
> Franklin T. Adams-Watters
>
>
> -----Original Message-----
> From: Alonso Del Arte <alonso.delarte at gmail.com>
> To: Sequence Fanatics Discussion list <seqfan at list.seqfan.eu>
> Sent: Sun, Dec 15, 2013 11:39 am
> Subject: [seqfan] First fini sequence in the table?
>
>
> As most of us know, for a long time Neil excluded finite sequences, though
> he made exceptions for sequences not known to be infinite (e.g., Mersenne
> primes) and "for certain important number-theoretic sequences,such as
> Euler's idoneal (or suitable) numbers."
>
> This raises the question: was A926 the first sequence in the OEIS known to
> be finite? At what point were the keywords fini and full accepted?
>
> Al
>
> --
> Alonso del Arte
> Author at SmashWords.com<https://www.smashwords.com/profile/view/
> AlonsoDelarte>
> Musician at ReverbNation.com <http://www.reverbnation.com/alonsodelarte>
>
>
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