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 A063186 #8 Jan 02 2022 20:24:55
%S A063186 1,4,6,13,16,31,131,231,578,905,1649,4810,5999,10249,11962,21338,
%T A063186 229345,404066,772217,1646462,2129025,235494066,559730937,1287457726,
%U A063186 1549953698,2919657850,23892156516,52085560558,70347157214
%N A063186 Engel expansion of Sum_{k>=0} 1/(3 + k)^k.
%C A063186 Shgz(3) = 1.2950786268784303709733480860835436581...
%t A063186 ToEngel[ x_, n_Integer ] := Rest@First@Transpose@NestList[ {Ceiling[ 1/# ], #}&[ Times@@#-1 ]&, {1, Abs[ x ]+1}, n ]
%Y A063186 Cf. A006784 for definition of Engel expansion.
%K A063186 nonn,easy,nice
%O A063186 1,2
%A A063186 _Olivier Gérard_, Jul 10 2001