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 A140145 #8 Jan 02 2024 09:01:01
%S A140145 1,9,12,76,81,297,304,816,825,1825,1836,3564,3577,6321,6336,10432,
%T A140145 10449,16281,16300,24300,24321,34969,34992,48816,48841,66417,66444,
%U A140145 88396,88425,115425,115456,148224,148257,187561,187596,234252,234289,289161
%N A140145 a(1)=1, a(n)=a(n-1)+n^1 if n odd, a(n)=a(n-1)+ n^3 if n is even.
%F A140145 a(n)=a(n-1)+4a(n-2)-4a(n-3)-6a(n-4)+6a(n-5)+4a(n-6)-4a(n-7)-a(n-8)+a(n-9). G.f.: -x*(1+8*x-x^2+32*x^3-x^4+8*x^5+x^6)/((1+x)^4*(x-1)^5). [From _R. J. Mathar_, Feb 22 2009]
%t A140145 a = {}; r = 1; s = 3; Do[k = 0; Do[k = k + (Sin[Pi m/2]^2) m^r + (Cos[Pi m/2]^2) m^s, {m, 1, n}]; AppendTo[a, k], {n, 1, 100}]; a (*Artur Jasinski*)
%Y A140145 Cf. A000027, A000217, A000330, A000537, A000538, A000539, A136047, A140113.
%K A140145 nonn
%O A140145 1,2
%A A140145 _Artur Jasinski_, May 12 2008