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 A280094 #10 Feb 16 2025 08:33:38
%S A280094 1,2,3,6,8,12,13,15,17,19,1063,1155,2574,2662,3595,3723,4370,21530,
%T A280094 28927,32662,73255,92895,5133189,13626701,17852908,392678721,
%U A280094 715595109,3993107840,39941257169,43578446054,1686996293054,4244526044926,78467829696572,111290944386765
%N A280094 Pierce Expansion of cot(1).
%H A280094 G. C. Greubel, <a href="/A280094/b280094.txt">Table of n, a(n) for n = 0..1000</a>
%H A280094 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PierceExpansion.html">Pierce Expansion</a>
%H A280094 Wikipedia, <a href="http://en.wikipedia.org/wiki/Engel_expansion">Engel Expansion</a>
%t A280094 PierceExp[A_, n_] := Join[Array[1 &, Floor[A]], First@Transpose@ NestList[{Floor[1/Expand[1 - #[[1]] #[[2]]]], Expand[1 - #[[1]] #[[2]]]} &, {Floor[1/(A - Floor[A])], A - Floor[A]}, n - 1]]; PierceExp[N[Cot[1] , 7!], 50]
%Y A280094 Cf. A073449 (cot(1)).
%K A280094 nonn
%O A280094 0,2
%A A280094 _G. C. Greubel_, Dec 25 2016