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A192596 Monotonic ordering of set S generated by these rules:  if x and y are in S and 3x+4y is a prime, then 3x+4y is in S, and 1 is in S. 2
1, 7, 31, 97, 127, 409, 601, 769, 1231, 1657, 1831, 2017, 2311, 3079, 3169, 3457, 3631, 3697, 3943, 4201, 4999, 5479, 5521, 5881, 6079, 6151, 6607, 6961, 7057, 7129, 7321, 7417, 7687, 8089, 8161, 8431, 9127, 9241, 9337, 9511, 9631, 9871, 10009 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

See the discussions at A192476 and A192580.

LINKS

Table of n, a(n) for n=1..43.

MATHEMATICA

start = {1}; primes = Table[Prime[n], {n, 1, 10000}];

f[x_, y_] := If[MemberQ[primes, 3 x + 4 y], 3 x + 4 y]

b[x_] :=

  Block[{w = x},

   Select[Union[

     Flatten[AppendTo[w,

       Table[f[w[[i]], w[[j]]], {i, 1, Length[w]}, {j, 1,

         Length[w]}]]]], # < 20000 &]];

t = FixedPoint[b, start]    (* A192596 *)

PrimePi[t]   (* A192597 *)

CROSSREFS

Cf. A192574, A192580, A192597.

Sequence in context: A205801 A193437 A199921 * A055899 A218956 A139876

Adjacent sequences:  A192593 A192594 A192595 * A192597 A192598 A192599

KEYWORD

nonn

AUTHOR

Clark Kimberling, Jul 05 2011

STATUS

approved

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Last modified February 28 10:55 EST 2020. Contains 332323 sequences. (Running on oeis4.)