A120721 Partial sums of A079645.

1, 3, 6, 10, 15, 21, 28, 36, 46, 58, 72, 88, 106, 126, 148, 172, 198, 225, 255, 288, 324, 363, 405, 450, 498, 549, 603, 660, 720, 783, 847, 915, 987, 1063, 1143, 1227, 1315, 1407, 1503, 1603, 1707, 1815, 1927, 2043, 2163, 2287, 2412, 2542, 2677, 2817, 2962, 3112, 3267

Offset

1,2

Links

G. C. Greubel, Table of n, a(n) for n = 1..10000

Formula

a(n) = Sum_{j=1..n} A079645(j).

a(n) ~ 2^(5/2)*n^(5/2)/(5*3^(3/2)) - 5*n^2/6. - Vaclav Kotesovec, Oct 13 2024

Mathematica

Accumulate[Select[Range[300], Divisible[#, Floor[CubeRoot[#]]]&]] (* Harvey P. Dale, Jun 19 2023 *)

Prog

(Magma)
A079645:=[n: n in [1..500] | n mod Floor(n^(1/3)) eq 0 ];
[(&+[A079645[k]: k in [1..n]]): n in [1..100]]; // G. C. Greubel, Jul 20 2023
(SageMath)
A079645=[j for j in (1..500) if j%(floor(j^(1/3)))==0]
def A120721(n): return sum(A079645[k] for k in range(n+1))
[A120721(n) for n in range(101)] # G. C. Greubel, Jul 20 2023

Crossrefs

Cf. A079645, A032378, A112873.

Sequence in context: A069792 A194153 A025737 * A122056 A358038 A025706

Adjacent sequences: A120718 A120719 A120720 * A120722 A120723 A120724

Keyword

nonn

Author

N. J. A. Sloane, Oct 29 2006

Status

approved