A066823 Primes in the main diagonal of the Stolarsky array (cf. A035506).

157, 6011, 55717, 74636904300223, 1524920857037139836753, 533561095785570791522387803, 960826779344998235261901369163166807780807

Offset: 1

Author

Randall L Rathbun, Jan 25 2002

Keywords

• easy
• nonn

Comments

Corresponding row/column numbers of the array are 6, 12, 16, 57, 91, 117, 189, 597, 707, 1729, 3933, (through 5000). The values in row/column 597, 707, ... are probable primes.

Crossrefs

Cf. A035506.

Programs

PARI

Stolarsky(r,c) = tau=(1+sqrt(5))/2; a=floor(r*(1+tau)-tau/2); b=round(a*tau); if(c==1,a, if(c==2,b, for(i=1,c-2,d=a+b; a=b; b=d; ); d))
for(x=1,5000,if(isprime(p=Stolarsky(x,x)),print1(p,",")))

Extensions

Edited by Klaus Brockhaus, May 26 2003

Edited by T. D. Noe, Oct 30 2008