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 A120721 #15 Oct 13 2024 03:57:57
%S A120721 1,3,6,10,15,21,28,36,46,58,72,88,106,126,148,172,198,225,255,288,324,
%T A120721 363,405,450,498,549,603,660,720,783,847,915,987,1063,1143,1227,1315,
%U A120721 1407,1503,1603,1707,1815,1927,2043,2163,2287,2412,2542,2677,2817,2962,3112,3267
%N A120721 Partial sums of A079645.
%H A120721 G. C. Greubel, <a href="/A120721/b120721.txt">Table of n, a(n) for n = 1..10000</a>
%F A120721 a(n) = Sum_{j=1..n} A079645(j).
%F A120721 a(n) ~ 2^(5/2)*n^(5/2)/(5*3^(3/2)) - 5*n^2/6. - _Vaclav Kotesovec_, Oct 13 2024
%t A120721 Accumulate[Select[Range[300],Divisible[#,Floor[CubeRoot[#]]]&]] (* _Harvey P. Dale_, Jun 19 2023 *)
%o A120721 (Magma)
%o A120721 A079645:=[n: n in [1..500] | n mod Floor(n^(1/3)) eq 0 ];
%o A120721 [(&+[A079645[k]: k in [1..n]]): n in [1..100]]; // _G. C. Greubel_, Jul 20 2023
%o A120721 (SageMath)
%o A120721 A079645=[j for j in (1..500) if j%(floor(j^(1/3)))==0]
%o A120721 def A120721(n): return sum(A079645[k] for k in range(n+1))
%o A120721 [A120721(n) for n in range(101)] # _G. C. Greubel_, Jul 20 2023
%Y A120721 Cf. A079645, A032378, A112873.
%K A120721 nonn
%O A120721 1,2
%A A120721 _N. J. A. Sloane_, Oct 29 2006