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 A325438 #14 May 30 2019 01:16:06 %S A325438 5,8,12,18,20,22,25,28,30,31,33,37,39,41,42,44,46,47,49,53,54,58,60, %T A325438 61,63,67,69,74,84,86,88,92,93,94,96,100,102,104,105,106,109,110,114, %U A325438 117,119,120,125,128,133,138,143,145,146,153,155,156,158,160,165 %N A325438 Indices of primes of the form k^2 + 1 ending in 1. %C A325438 This sequence is presumably infinite. See 1st comment of A002496. %H A325438 Robert Israel, <a href="/A325438/b325438.txt">Table of n, a(n) for n = 1..10000</a> %F A325438 A002496(a(n)) mod 10 = 1. %p A325438 P:=[seq(k mod 10,k=select(isprime,[2,seq(4*i^2+1,i=1..10000)]))]: %p A325438 seq(`if`(P[i] mod 10 = 1,i,NULL),i=1..nops(P)); %Y A325438 Cf. A002496, A325437, A325439. %K A325438 nonn,base %O A325438 1,1 %A A325438 _Martin Renner_, Apr 27 2019