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 A271991 #6 Jan 11 2020 15:57:47
%S A271991 10,29,65,125,215,284,363,452,551,660,779,907,1045,1193,1351,1519,
%T A271991 1697,1885,2083,2291,2509,2737,2975,3222,3479,3746,4023,4310,4607,
%U A271991 4914,5231,5558,5895,6242,6599,6966,7343,7730,8127,8534,8951
%N A271991 g_n(10) where g is the weak Goodstein function defined in A266202.
%C A271991 For more info see A266201-A266202.
%t A271991 g[k_, n_] := If[k == 0, n, Total@ Flatten@ MapIndexed[#1 (k + 2)^(#2 - 1) &, Reverse@ IntegerDigits[#, k + 1]] &@ g[k - 1, n] - 1]; Table[g[n, 10], {n, 0, 40}]
%Y A271991 Cf. A271557: G_n(10).
%Y A271991 Weak Goodstein sequences: A137411: g_n(11); A265034: g_n(266); A267647: g_n(4); A267648: g_n(5); A271987: g_n(6); A271988: g_n(7); A271989: g_n(8); A271990: g_n(9); A266202: g_n(n); A266203: a(n)=k such that g_k(n)=0;
%K A271991 nonn,fini
%O A271991 0,1
%A A271991 _Natan Arie Consigli_, May 22 2016