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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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

See the discussions at A192476 and A192580.

LINKS

Table of n, a(n) for n=1..35.

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

Adjacent sequences:  A192586 A192587 A192588 * A192590 A192591 A192592

KEYWORD

nonn,fini,full

AUTHOR

Clark Kimberling, Jul 05 2011

STATUS

approved

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Last modified February 26 02:19 EST 2020. Contains 332270 sequences. (Running on oeis4.)