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 A229291 #21 Jul 03 2017 14:22:29
%S A229291 2,3,5,7,11,23,31,43,47,67,71,139,151,211,283,311,331,431,463,659,683,
%T A229291 691,863,907,947,967,1051,1151,1291,1303,1319,1367,1427,1511,1699,
%U A229291 1867,1979,1987,2011,2111,2131,2311,2351,2531,3011,3023,3083,3323,3851,4099
%N A229291 n is in the sequence if n is prime, (n-1)/5^A112765(n-1) is a squarefree number, A112765(n-1) < 3 and every prime divisor of n-1 is in the sequence.
%C A229291 If n is in A226963 then n is some product of elements of this sequence.
%t A229291 fa = FactorInteger; free[n_] := n == Product[fa[n][[i, 1]], {i,
%t A229291 Length[fa[n]]}]; Os[b_, 1] = True; Os[b_, 2] = True; Os[ b_, b_] = True; Os[b_, n_] := Os[b, n] = PrimeQ[n] && free[(n - 1)/b^IntegerExponent[n - 1,b]] && IntegerExponent[n - 1, b] < 3 && Union@Table[Os[b, fa[n - 1][[i, 1]]], {i, Length[fa[n - 1]]}] == {True}; G[b_] := Select[Prime [Range[2000]], Os[b, #] &]; G[5]
%Y A229291 Cf. A112765, A226963, A229289, A229290.
%K A229291 nonn
%O A229291 1,1
%A A229291 _José María Grau Ribas_, Oct 06 2013