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 A067912 #15 Dec 26 2016 05:31:14
%S A067912 1,13,15,19,132,1474,1977,10392,12992,44777,59412,170685,217607,
%T A067912 704791,818133,1387423,2208674,3206215,12732462,13962681,24593168,
%U A067912 39744274,55804517,130269696,426536424,546807194,1030799587,1139987135
%N A067912 Engel expansion of zeta(4) = Pi^4/90 = Sum_{i>0} 1/i^4.
%H A067912 G. C. Greubel, <a href="/A067912/b067912.txt">Table of n, a(n) for n = 1..1000</a>
%t A067912 EngelExp[A_, n_] := Join[Array[1 &, Floor[A]], First@Transpose@
%t A067912 NestList[{Ceiling[1/Expand[#[[1]] #[[2]] - 1]], Expand[#[[1]] #[[2]] - 1]/1} &, {Ceiling[1/(A - Floor[A])], (A - Floor[A])/1}, n - 1]]; EngelExp[N[Pi^4/90, 7!], 20] (* _G. C. Greubel_, Dec 26 2016 *)
%Y A067912 See A006784 for explanation of Engel expansions.
%Y A067912 Cf. A059186, A053980.
%K A067912 easy,nonn
%O A067912 1,2
%A A067912 _Benoit Cloitre_, Mar 03 2002