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 A134642 #5 Nov 30 2023 12:19:04
%S A134642 0,1,15,21,27,30,39,45,54,57,75,78,99,108,114,120,135,141,147,156,177,
%T A134642 180,198,201,210,216,225,228,194,198,214,222,238,242,294,298,334,346,
%U A134642 358,366,414,422,434,446,482,486,538,542,558,566,582,586,694,698,714
%N A134642 Nonprime permutational numbers A134640.
%t A134642 a = {}; b = {}; Do[AppendTo[b, n]; w =Permutations[b]; Do[j = FromDigits[w[[m]], n + 1]; If[PrimeQ[j], AppendTo[a, j]], {m, 1, Length[w]}], {n, 0, 10}]; a (*Artur Jasinski*)
%t A134642 Select[Flatten[Table[FromDigits[#,n]&/@Permutations[Range[0,n-1]],{n,5}]],!PrimeQ[#]&] (* _Harvey P. Dale_, Nov 30 2023 *)
%Y A134642 Cf. A134640, A134641.
%K A134642 nonn
%O A134642 1,3
%A A134642 _Artur Jasinski_, Nov 05 2007, Nov 07 2007