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A192589
Monotonic ordering of set S generated by these rules: if x and y are in S and xy+3 is a prime, then xy+3 is in S, and 2 and 4 are in S.
1
2, 4, 7, 11, 17, 19, 31, 37, 41, 47, 71, 79, 97, 127, 151, 167, 191, 197, 257, 337, 397, 607, 677, 797, 1031, 1217, 1597, 2437, 2711, 3191, 4127, 4871, 4877, 10847, 43391
OFFSET
1,1
COMMENTS
See the discussions at A192476 and A192580.
MATHEMATICA
start = {2, 4}; primes = Table[Prime[n], {n, 1, 40000}];
f[x_, y_] := If[MemberQ[primes, x*y + 3], x*y + 3]
b[x_] :=
Block[{w = x},
Select[Union[
Flatten[AppendTo[w,
Table[f[w[[i]], w[[j]]], {i, 1, Length[w]}, {j, 1, i}]]]], # <
200000 &]];
t = FixedPoint[b, start] (* A192589 *)
CROSSREFS
Cf. A192476 and A192580.
Sequence in context: A153535 A116615 A053145 * A266448 A101978 A076273
KEYWORD
nonn,fini,full
AUTHOR
Clark Kimberling, Jul 05 2011
STATUS
approved