[seqfan] Re: R: Sequence related to A180919

[Joerg Arndt]

* Bruno Berselli <berselli.bruno at yahoo.it> [Jan 19. 2011 16:44]:
> Ciao, Joerg!

Don't forget Robert Israel, number theorist on duty  8-)


>  
>  
> ...perhaps the following sequence?

Much better!

Suggest NAME
"Number of squares of the form k^2 + n*k + 1 (k>0)."


Pari: (note the bounds need to be filled in)

N=100;  /* max N */
{ for (n=3, N,  /* n>2 to avoid infinitely many squares n^2+2*n+1 */
    ct = 0; /* count squares */
    nl =??? ; /* lower bound for search */
    nh =??? ; /* higher bound for search */
    for (k=nl, nh,  ct += issquare(k^2+n*k+1) );
    print1(ct,", ");
); }


> [...]  .  .  Is it so? Maybe it is a little repetitive, but it is an
> approach to the problem. Thanks ;)
> 

An independent check would indeed be useful.


>  
> Bruno
> [...]