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 A290136 #9 Jul 21 2017 05:32:21
%S A290136 1,3,4,5,6,8,9,10,13,14,17,18,19,26,33,38,46,62,82
%N A290136 Positive numbers that are not the sum of two nonprime squarefree numbers (A000469).
%C A290136 The sequence is conjectured to be complete.
%t A290136 nmax = 82; f[x_] := Sum[Boole[SquareFreeQ[k] && PrimeNu[k] != 1] x^k, {k, 1, nmax}]^2; b = Exponent[#, x] & /@ List @@ Normal[Series[f[x], {x, 0, nmax}]]; c = Complement[Range[nmax], b][[1 ;; 19]]
%Y A290136 Cf. A000469, A014092, A071068, A071331, A098235, A239508, A239509.
%K A290136 nonn,more
%O A290136 1,2
%A A290136 _Ilya Gutkovskiy_, Jul 20 2017