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 A154413 #8 Sep 17 2016 00:30:16
%S A154413 0,0,0,2,30,202,2016,14394,151290,1294478,15660744,162298842,
%T A154413 2274318228,27968231436,447527038848,6382757516250,114890215021650,
%U A154413 1865385066804550,37307710791708600,679562209260462054
%N A154413 a(n) = A006551(n) - A018224(n).
%H A154413 G. C. Greubel, <a href="/A154413/b154413.txt">Table of n, a(n) for n = 0..300</a>
%F A154413 a(n) = Eulerian[n,Floor[n/2]] - Binomial[n,Floor[n/2]]^2.
%t A154413 t[n_, k_] = Sum[(-1)^j Binomial[n + 1, j](k + 1 - j)^n, {j, 0, k + 1}];
%t A154413 a0 = Table[t[n, Floor[n/2]], {n, 1, 30}];
%t A154413 b0 = Table[Binomial[n, Floor[(n)/2]]^2, {n, 0, 29}];
%t A154413 a=a0-b0
%Y A154413 Cf. A006551, A018224.
%K A154413 nonn
%O A154413 0,4
%A A154413 _Roger L. Bagula_, Jan 09 2009