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A192590 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

%I

%S 2,4,5,7,11,13,17,19,23,31,41,43,59,73,79,83,89,163,233,313,353,463,

%T 929,1249,1409,4993

%N 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.

%C See the discussions at A192476 and A192580.

%t start = {2, 4}; primes = Table[Prime[n], {n, 1, 40000}];

%t f[x_, y_] := If[MemberQ[primes, x*y - 3], x*y - 3]

%t b[x_] :=

%t Block[{w = x},

%t Select[Union[

%t Flatten[AppendTo[w,

%t Table[f[w[[i]], w[[j]]], {i, 1, Length[w]}, {j, 1, i}]]]], # <

%t 200000 &]];

%t t = FixedPoint[b, start] (* A192590 *)

%Y Cf. A192476, A192580.

%K nonn,fini,full

%O 1,1

%A _Clark Kimberling_, Jul 05 2011

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Last modified October 6 03:55 EDT 2022. Contains 357261 sequences. (Running on oeis4.)