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

1,1

COMMENTS

See the discussion at A192580.

LINKS

Table of n, a(n) for n=1..28.

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

Adjacent sequences:  A192579 A192580 A192581 * A192583 A192584 A192585

KEYWORD

nonn,fini,full

AUTHOR

Clark Kimberling, Jul 04 2011

STATUS

approved

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Last modified January 19 00:40 EST 2020. Contains 331030 sequences. (Running on oeis4.)