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 A138906 #6 Jun 23 2025 10:03:38
%S A138906 7,37,73,241,211,433,463,769,811,1321,1321,2089,1951,2689,2791,4513,
%T A138906 3469,5077,6271,6121,6427,7129,7177,10369,7951,10453,10531,13441,
%U A138906 15139,12601,18229,15937,17623,21013,15331,24841,23977,26449,24571,24481
%N A138906 a(n) is n-th prime == 1 (mod 6n).
%t A138906 a[n_]:=Module[{p=1,cnt=0},Until[cnt==n,If[Mod[Prime[p],6n]==1,cnt++];p++];Prime[p-1]];Array[a,40] (* _James C. McMahon_, Jun 23 2025 *)
%Y A138906 Cf. A138905, A138907.
%K A138906 nonn
%O A138906 1,1
%A A138906 _Zak Seidov_, Apr 03 2008