This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A192596 #4 Mar 30 2012 18:57:36 %S A192596 1,7,31,97,127,409,601,769,1231,1657,1831,2017,2311,3079,3169,3457, %T A192596 3631,3697,3943,4201,4999,5479,5521,5881,6079,6151,6607,6961,7057, %U A192596 7129,7321,7417,7687,8089,8161,8431,9127,9241,9337,9511,9631,9871,10009 %N 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. %C A192596 See the discussions at A192476 and A192580. %t A192596 start = {1}; primes = Table[Prime[n], {n, 1, 10000}]; %t A192596 f[x_, y_] := If[MemberQ[primes, 3 x + 4 y], 3 x + 4 y] %t A192596 b[x_] := %t A192596 Block[{w = x}, %t A192596 Select[Union[ %t A192596 Flatten[AppendTo[w, %t A192596 Table[f[w[[i]], w[[j]]], {i, 1, Length[w]}, {j, 1, %t A192596 Length[w]}]]]], # < 20000 &]]; %t A192596 t = FixedPoint[b, start] (* A192596 *) %t A192596 PrimePi[t] (* A192597 *) %Y A192596 Cf. A192574, A192580, A192597. %K A192596 nonn %O A192596 1,2 %A A192596 _Clark Kimberling_, Jul 05 2011