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 A192613 Monotonic ordering of set S generated by these rules:  if x and y are in S and x^2+2y^2 is a prime, then x^2+2y^2 is in S, and 1, 2, and 4 are in S. 3
 1, 2, 3, 4, 11, 17, 19, 41, 139, 251, 307, 379, 587, 1699, 3371 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS See the discussions at A192476 and A192580. LINKS MATHEMATICA start = {1, 2, 4}; primes = Table[Prime[n], {n, 1, 20000}]; f[x_, y_] := If[MemberQ[primes, x^2 + 2 y^2], x^2 + 2 y^2] b[x_] :=   Block[{w = x},    Select[Union[      Flatten[AppendTo[w,        Table[f[w[[i]], w[[j]]], {i, 1, Length[w]}, {j, 1,          Length[w]}]]]], # < 30000 &]]; t = FixedPoint[b, start] (* A192613 *) CROSSREFS Cf. A192612, A192476, A192580. Sequence in context: A141704 A061919 A328883 * A002098 A301318 A297180 Adjacent sequences:  A192610 A192611 A192612 * A192614 A192615 A192616 KEYWORD nonn,fini,full AUTHOR Clark Kimberling, Jul 05 2011 STATUS approved

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Last modified September 27 16:11 EDT 2020. Contains 337383 sequences. (Running on oeis4.)