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 A128131 #10 Feb 24 2015 05:40:07 %S A128131 1,-4,0,0,-16384,1048576,0,0,17592186044416,-18014398509481984,0,0, %T A128131 -1237940039285380274899124224,20282409603651670423947251286016,0,0, %U A128131 5708990770823839524233143877797980545530986496 %N A128131 a(n) = 2^A000096(n)*A128130(n). %F A128131 a(n) = 2^n * 2^C(n+1,2) * A128130(n); %p A128131 A128131 := proc(n) %p A128131 2^(n*(n+3)/2)*A128130(n) ; %p A128131 end proc: # _R. J. Mathar_, Feb 24 2015 %Y A128131 Cf. A036442, A127945. %K A128131 easy,sign %O A128131 0,2 %A A128131 _Paul Barry_, Feb 15 2007 %E A128131 Incorrect NAME removed. - _R. J. Mathar_, Feb 24 2015