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 A280103 #8 Feb 16 2025 08:33:38
%S A280103 9,59,258,1621,41718,163096,18032586,372522402,4134015746,32288273026,
%T A280103 351014976193,4870192684354,16888414224772,69504582263701,
%U A280103 605288885084501,142251062156316087,465610991052284457,1483900314571047497,5622121203907195494,23213137436116662167
%N A280103 Engel expansion of 1/e in the base Pi.
%H A280103 G. C. Greubel, <a href="/A280103/b280103.txt">Table of n, a(n) for n = 0..250</a>
%H A280103 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PierceExpansion.html">Pierce Expansion</a>
%H A280103 Wikipedia, <a href="http://en.wikipedia.org/wiki/Engel_expansion">Engel Expansion</a>
%t A280103 EngelExp[A_, n_] := Join[Array[Pi &, Floor[A]], First@Transpose@
%t A280103 NestList[{Ceiling[Pi/Expand[#[[1]] #[[2]] - 1]], Expand[#[[1]] #[[2]] - 1]/Pi} &, {Ceiling[Pi/(A - Floor[A])], (A - Floor[A])/Pi}, n - 1]]; EngelExp[N[1/E, 7!], 20]
%Y A280103 Cf. A232325, A280102.
%K A280103 nonn
%O A280103 0,1
%A A280103 _G. C. Greubel_, Dec 25 2016