A096274: checking/more terms

Peter Pein petsie at dordos.net
Fri Nov 16 00:31:39 CET 2007


zak seidov schrieb:
> A096274: checking/more terms
> 
> Neil, Bob, Jim, seqfans,
> 
> I've checked (and re-checked) terms in A096274 and
> found them OK:
> 
> %S A096274
> 2,8,13,20,25,595,1044,7932,74247,14693476,16766626,24072338,72643740,
> 1881945888,3304284638,5163731431. 
> 
> Also, I'd found three more terms:
> 5669949197, 16209038688, 23714508404.
> 
> Some C++/PARI gurus
> may wish to check the last three terms 
> (and find more).
> Thanks, Zak 
> 

Hi Zak,

with a little C-program (see below) I get almost the same values. The
only difference is a(19)=23714508403 instead of 23714508404.
Additionally my computer assumes a(20) to be 56796564073.

Peter

the program:

#include <stdio.h>

main(int argc, char *argv[])
{
long long a0=1, a1=1, n=1, tmp, nmax;

  if (argc != 2) {
    fprintf(stderr,"%s n\ncalculates the indices of the first n zeroes
in http://www.research.att.com/~njas/sequences/A096535\n",argv[0]);
    return(1);
  }
  nmax=atol(argv[1]);
  while (nmax-- > 0) {
    while(a1 != 0) {
      tmp = (a0 + a1) % ++n; a0 = a1; a1 = tmp;
    }
    printf("%lld\n",n++); a1 = a0; a0 = 0;
  }
  return 0;
}

the output:

petsie at leierkasten:~$ time ./a096274 20
...
no differences here
...
23714508403
56796564073

real    51m43.296s
user    33m16.801s
sys     0m0.744s




Dear Seqfans

Although Eric Weisstein's site has many links
to the OEIS, it seems that the Wikipedia has very few.

I noticed this because a correspondent said A002067 was wrong
because it disagreed with the entry  http://en.wikipedia.org/wiki/Error_function

In fact the sequence he should have been looking at was A092676.

So I went in and edited that entry by mentioning which

I think the world only benefits by having more links like that, so I would
like to encourage seqfans to add more OEIS links
to the Wikipedia

Neil





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