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 A216351 #13 Sep 22 2015 15:52:29 %S A216351 1,1,2,12,156,3160,87990,3218628,150271520,8710554816,610951827960, %T A216351 50770346742720,4919197411068072,548907184341479808, %U A216351 69823173142960626480,10034787531626188107840,1616352219917942008147200,289720383156740969786941440 %N A216351 n-th derivative of x^(x^(n-1)) at x=1. %C A216351 x^(x^(n-1)) = (((x^x)^x)^ ... )^x with n x's. %H A216351 Alois P. Heinz, <a href="/A216351/b216351.txt">Table of n, a(n) for n = 0..275</a> %F A216351 a(n) = n! * [x^n] (x+1)^((x+1)^(n-1)). %F A216351 a(n) = A216349(n,1) = A216350(n,A000081(n)) for n>0. %p A216351 a:= n-> n! *coeff(series( (x+1)^((x+1)^(n-1)) , x, n+1), x, n): %p A216351 seq(a(n), n=0..20); %Y A216351 Cf. A000081, A216349, A216350, A215703. %K A216351 nonn %O A216351 0,3 %A A216351 _Alois P. Heinz_, Sep 04 2012