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A192582
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.
3
2, 4, 5, 6, 11, 13, 17, 23, 31, 37, 47, 53, 67, 79, 103, 107, 139, 149, 223, 269, 283, 317, 557, 619, 643, 1699, 2477, 3343
OFFSET
1,1
COMMENTS
See the discussion at A192580.
MATHEMATICA
start = {2, 4, 6}; primes = Table[Prime[n], {n, 1, 10000}];
f[x_, y_] := If[MemberQ[primes, x*y + 1], x*y + 1]
b[x_] :=
Block[{w = x},
Select[Union[
Flatten[AppendTo[w,
Table[f[w[[i]], w[[j]]], {i, 1, Length[w]}, {j, 1, i}]]]], # <
10000000 &]];
t = FixedPoint[b, start] (* A192582 *)
CROSSREFS
Cf. A192476.
Sequence in context: A278507 A113631 A202101 * A101951 A171166 A194607
KEYWORD
nonn,fini,full
AUTHOR
Clark Kimberling, Jul 04 2011
STATUS
approved