A192590 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.

2, 4, 5, 7, 11, 13, 17, 19, 23, 31, 41, 43, 59, 73, 79, 83, 89, 163, 233, 313, 353, 463, 929, 1249, 1409, 4993

Offset: 1

Author

Clark Kimberling, Jul 05 2011

Keywords

• nonn
• fini
• full

Comments

See the discussions at A192476 and A192580.

Crossrefs

Cf. A192476, A192580.

Programs

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]    (* A192590 *)