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A120721
Partial sums of A079645.
3
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
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
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Oct 29 2006
STATUS
approved