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A358038
Partial sums of the cubefree numbers.
1
1, 3, 6, 10, 15, 21, 28, 37, 47, 58, 70, 83, 97, 112, 129, 147, 166, 186, 207, 229, 252, 277, 303, 331, 360, 390, 421, 454, 488, 523, 559, 596, 634, 673, 714, 756, 799, 843, 888, 934, 981, 1030, 1080, 1131, 1183, 1236, 1291, 1348, 1406, 1465, 1525, 1586, 1648, 1711
OFFSET
1,2
COMMENTS
First differs from A025706 and A025730 at n = 14.
The analogous sequence with squarefree numbers is A173143.
LINKS
Zhu Weiyi, On the cube free number sequences, Smarandache Notions J., Vol. 14 (2004), pp. 199-202.
FORMULA
a(n) = Sum_{k=1..n} A004709(k).
a(n) = (zeta(3)/2)*n^2 + O(n^(3/2+eps)) (Weiyi, 2004).
MATHEMATICA
Accumulate[Select[Range[100], Max[FactorInteger[#][[;; , 2]]] < 3 &]]
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Oct 29 2022
EXTENSIONS
Corrected by Amiram Eldar, Jan 02 2024
STATUS
approved