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.
%I A376431 #15 Sep 27 2024 07:18:47 %S A376431 3,13,11,3,5,3,10949,3,11,7,3,3,5,3,23,13,29,3,3,5,3,3,41,11,3,5,3,53, %T A376431 3,7,3,5,17,3,37,3,3,3,83,43,89,3,5,3,7,3,3,3,113,3,29,7,3,5,21589, %U A376431 131,67,3,3,5,3,73,3,5,3,79,3,3,173,3,11,179,3,3,3,191 %N A376431 a(n) is the least odd prime factor of prime(n)^prime(n)-1. %H A376431 Hugo Pfoertner, <a href="/A376431/b376431.txt">Table of n, a(n) for n = 1..6542</a> %F A376431 a(n) = A078701(A088730(n)). - _Michel Marcus_, Sep 27 2024 %o A376431 (PARI) a376431(n) = my(pp=prime(n)^prime(n)-1); forprime (p=3, oo, if(pp%p==0, return(p))) %Y A376431 Cf. A078701, A088730, A376432. %K A376431 nonn %O A376431 1,1 %A A376431 _Hugo Pfoertner_, Sep 27 2024