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 A281434 #11 Oct 06 2017 02:05:12
%S A281434 1,3,12,30,64,113,188,285,415,577,780,1017,1312,1648,2044,2489,3008,
%T A281434 3583,4236,4953,5760,6638,7611,8664,9822,11069,12426,13880,15455,
%U A281434 17131,18940,20855,22912,25083,27404,29844,32448,35178,38075,41109,44320,47672,51212
%N A281434 Number of terms in the fully expanded n-th derivative of x^(x^x).
%e A281434 For n=1, the 1st derivative of x^(x^x) is x^(x^x+x-1) + x^(x^x+x)*log(x) + x^(x^x+x)*log^2(x), so a(1) = 3.
%t A281434 Join[{1}, Length /@ Rest[NestList[Expand[D[#, x]] &, x^x^x, 42]]]
%Y A281434 Cf. A293239.
%K A281434 nonn
%O A281434 0,2
%A A281434 _Vladimir Reshetnikov_, Oct 05 2017