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A192592 Monotonic ordering of set S generated by these rules:  if x and y are in S and 3x+2y is a prime, then 3x+2y is in S, and 1 is in S. 3
1, 5, 13, 17, 29, 37, 41, 53, 61, 73, 89, 97, 109, 113, 137, 149, 157, 173, 181, 193, 197, 229, 233, 241, 257, 269, 277, 281, 293, 313, 317, 337, 349, 353, 373, 389, 397, 401, 409, 421, 433, 449, 457, 461, 509, 521, 541, 557, 569, 577, 593, 601, 613, 617 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

See the discussions at A192476 and A192580.

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..609

MATHEMATICA

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

f[x_, y_] := If[MemberQ[primes, 2 x + 3 y], 2 x + 3 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]}]]]], # < 1000 &]];

t = FixedPoint[b, start]     (* A192592 *)

PrimePi[t]    (* A192593 *)

CROSSREFS

Cf. A192476, A192580, A192593.

Sequence in context: A002144 A280084 A319287 * A349900 A347163 A111055

Adjacent sequences:  A192589 A192590 A192591 * A192593 A192594 A192595

KEYWORD

nonn

AUTHOR

Clark Kimberling, Jul 05 2011

STATUS

approved

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Last modified August 7 12:01 EDT 2022. Contains 355985 sequences. (Running on oeis4.)