cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A105050 a(0)=2, a(n) is the smallest prime of the form a(n-1)*k^2 + 1.

Original entry on oeis.org

2, 3, 13, 53, 30529, 122117, 17584849, 70339397, 22789964629, 11030342880437, 9927308592393301, 91490075987496662017, 23421459452799145476353, 918214896387537699254943013, 528891780319221714770847175489, 8665362928750128574805560123211777, 311953065435004628693000164435623973
Offset: 0

Views

Author

John L. Drost, Apr 04 2005

Keywords

Examples

			a(5) = 30529 = 53*24^2 + 1 is the smallest prime of the form 53*k^2 + 1.
		

Crossrefs

Programs

  • PARI
    lista(nn) = my(k, p=2); print1(p); for(n=1, nn, k=1; while(!isprime(p*k^2+1), k++); print1(", ", p=p*k^2+1)); \\ Jinyuan Wang, Aug 02 2021

Extensions

a(15)-a(16) from Jinyuan Wang, Aug 02 2021