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 A226817 #3 Jun 19 2013 02:26:42
%S A226817 2,5,8,11,17,23,50,53,65,71,113,257,263,305,344,347,359,407,599,1025,
%T A226817 1031,1073,1367,2402,2405,2417,2465,2657,3425,4097,4103,4145,4439,
%U A226817 6497,16385,16391,16433,16727,16808,16811,16823,16871,17063,17831,18785,20903
%N A226817 Numbers of the form 4^j + 7^k, for j and k >= 0.
%H A226817 T. D. Noe, <a href="/A226817/b226817.txt">Table of n, a(n) for n = 1..10000</a>
%t A226817 a = 4; b = 7; mx = 30000; Union[Flatten[Table[a^n + b^m, {m, 0, Log[b, mx]}, {n, 0, Log[a, mx - b^m]}]]]
%Y A226817 Cf. A004050 (2^j + 3^k), A226806-A226832 (cases to 8^j + 9^k).
%K A226817 nonn
%O A226817 1,1
%A A226817 _T. D. Noe_, Jun 19 2013