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 A178570 #26 Jun 27 2024 22:18:12 %S A178570 2,3,5,7,13,20,24,26,28,30,31,32,36,41,43,49,52,62,64,67,69,73,77,81, %T A178570 83,86,87,89,103,105,109,116,121,129,135,142,144,148,152,156,158,159, %U A178570 163,168,171,173,182,190,192,196,206,208,212,215,217,219,223,225,231,234,236 %N A178570 Numbers k such that prime(k+1) == 1 (mod (prime(k+2) - prime(k))). %H A178570 G. C. Greubel, <a href="/A178570/b178570.txt">Table of n, a(n) for n = 1..10000</a> %e A178570 2 is a term because prime(2+1) mod (prime(2+2) - prime(2)) = 5 mod 4 = 1. %t A178570 fQ[n_] := Mod[Prime[n+1], Prime[n+2] - Prime[n]] == 1; Select[ Range@ 250, fQ] %o A178570 (PARI) isok(n) = prime(n+1) % (prime(n+2) - prime(n)) == 1; \\ _Michel Marcus_, Jan 31 2019 %Y A178570 Cf. A067185. %K A178570 nonn %O A178570 1,1 %A A178570 _Juri-Stepan Gerasimov_, Jan 01 2011