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 A226831 #7 Feb 18 2021 21:29:48
%S A226831 2,8,10,16,50,58,82,88,130,344,352,424,730,736,778,1072,2402,2410,
%T A226831 2482,3130,6562,6568,6610,6904,8962,16808,16816,16888,17536,23368,
%U A226831 59050,59056,59098,59392,61450,75856,117650,117658,117730,118378,124210,176698,531442
%N A226831 Numbers of the form 7^j + 9^k, for j and k >= 0.
%H A226831 T. D. Noe, <a href="/A226831/b226831.txt">Table of n, a(n) for n = 1..10000</a>
%t A226831 a = 7; b = 9; mx = 600000; Union[Flatten[Table[a^n + b^m, {m, 0, Log[b, mx]}, {n, 0, Log[a, mx - b^m]}]]]
%o A226831 (PARI) list(lim)=my(v=List(),J,K); for(j=0,logint((lim\=1)-1,7), J=7^j; K=1; while(J+K<=lim, listput(v,J+K); K*=9)); Set(v) \\ _Charles R Greathouse IV_, Feb 18 2021
%Y A226831 Cf. A004050 (2^j + 3^k), A226806-A226832 (cases to 8^j + 9^k).
%Y A226831 Cf. A226795 ((7^j + 9^k)/2).
%K A226831 nonn,easy
%O A226831 1,1
%A A226831 _T. D. Noe_, Jun 19 2013