cp's OEIS Frontend

A192587 Monotonic ordering of set S generated by these rules: if x and y are in S and xy-1 is a prime, then xy-1 is in S, and 2, 4, and 6 are in S.

%I A192587 #4 Mar 30 2012 18:57:35
%S A192587 2,3,4,5,6,7,11,13,17,19,23,29,37,41,43,67,73,101,113,137,163,173,257,
%T A192587 401,547,677,691,821,977,1093,1381,2707,3907,5413,5861
%N A192587 Monotonic ordering of set S generated by these rules:  if x and y are in S and xy-1 is a prime, then xy-1 is in S, and 2, 4, and 6 are in S.
%C A192587 See the discussions at A192476 and A192580.
%t A192587 start = {2, 4, 6}; primes = Table[Prime[n], {n, 1, 10000}];
%t A192587 f[x_, y_] := If[MemberQ[primes, x*y - 1], x*y - 1]
%t A192587 b[x_] :=
%t A192587   Block[{w = x},
%t A192587    Select[Union[
%t A192587      Flatten[AppendTo[w,
%t A192587        Table[f[w[[i]], w[[j]]], {i, 1, Length[w]}, {j, 1, i}]]]], # <
%t A192587       50000 &]];
%t A192587 t = FixedPoint[b, start]   (* A192587 *)
%Y A192587 Cf. A192476, A192580, A192586, A192588.
%K A192587 nonn,fini,full
%O A192587 1,1
%A A192587 _Clark Kimberling_, Jul 05 2011