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 A094647 #6 Jul 25 2015 00:44:20
%S A094647 -1,0,513,61440,9665625,2173796352,678117659345,281470681743360,
%T A094647 150094436937708753,99999989760000000000,81402748802521459701993,
%U A094647 79496847166870496697384960,91733330190787463785195879433
%N A094647 a(n) = n^(2n) - (2n)^n.
%e A094647 a(3) = 513 because 3^(2*3) - (2*3)^3 = 3^6 - 6^3 = 513.
%t A094647 a[n_] := n^n(n^n - 2^n); Table[a[n], {n, 13}] (* _Robert G. Wilson v_, May 24 2004 *)
%Y A094647 Cf. A007925, A046065.
%K A094647 easy,sign
%O A094647 1,3
%A A094647 Gregory S. Thoman (fealuinix(AT)yahoo.com), May 18 2004
%E A094647 More terms from _Emeric Deutsch_, _Robert G. Wilson v_ and Pab Ter (pabrlos(AT)yahoo.com), May 24 2004