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 A164583 #9 May 10 2024 11:09:29 %S A164583 1,36,400,3136,20736,123904,692224,3686400,18939904,94633984, %T A164583 462422016,2218786816,10485760000,48922361856,225754218496, %U A164583 1031865892864,4677219385344,21045339750400,94076963651584,418089296461824 %N A164583 a(n) = 4^n*(2n + 1)^2. %C A164583 The aerated signed sequence 0,-1,0,36,0,-400,... with general term -(-4)^((n-1)/2)*n^2*(1-(-1)^n)/2 %C A164583 is the Hankel transform of the aeration 0,1,0,6,0,30,0,140,... of A002457. %H A164583 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (12,-48,64). %F A164583 G.f.: (1+24x+16x^2)/(1-4x)^3. %K A164583 easy,nonn %O A164583 0,2 %A A164583 _Paul Barry_, Aug 17 2009