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 A350222 #20 Oct 27 2023 21:17:01
%S A350222 1,7,25,57,114,194,310,460,658,902,1200,1557,1981,2474,3045,3690,4431,
%T A350222 5257,6186,7212,8350,9601,10969,12461,14088,15844,17746,19791,21990,
%U A350222 24343,26859,29539,32399,35434,38655,42060,45671,49468,53480,57698,62137,66793,71681
%N A350222 a(n) = Sum_{k=1..n} (-1)^(k+1) * floor((n/k)^3).
%F A350222 a(n) = A309082(n^3).
%t A350222 a[n_] := Sum[(-1)^(k + 1)*Floor[(n/k)^3], {k, 1, n}]; Array[a, 50] (* _Amiram Eldar_, Dec 20 2021 *)
%o A350222 (PARI) a(n) = sum(k=1, n, (-1)^(k+1)*(n^3\k^3));
%o A350222 (Python)
%o A350222 def A350222(n): return (m:=n**3)+sum(m//k**3 if k&1 else -(m//k**3) for k in range(2,n+1)) # _Chai Wah Wu_, Oct 27 2023
%Y A350222 Cf. A000578, A309082, A344675, A344721, A350221, A350224.
%K A350222 nonn
%O A350222 1,2
%A A350222 _Seiichi Manyama_, Dec 20 2021