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A347516 Number of divisors of n that are at most n^(1/3). 3
1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 2, 2, 1, 3, 1, 2, 2, 2, 1, 3, 1, 2, 2, 2, 1, 3, 1, 2, 2, 2, 1, 3, 1, 2, 2, 2, 1, 3, 1, 2, 2, 2, 1, 3, 1, 2, 2, 3, 1, 3, 1, 3, 2, 2, 1, 4, 1, 2, 2, 3, 1, 3, 1, 3, 2, 2, 1, 4, 1, 2, 2, 3, 1, 3, 1, 3, 2, 2, 1, 4, 1, 2, 2, 3, 1, 3, 1, 3, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,8

LINKS

Seiichi Manyama, Table of n, a(n) for n = 1..10000

FORMULA

G.f.: Sum_{k>=1} x^(k^3)/(1 - x^k).

MATHEMATICA

a[n_] := DivisorSum[n, 1 &, # <= n^(1/3) &]; Array[a, 100] (* Amiram Eldar, Sep 04 2021 *)

PROG

(PARI) a(n) = sumdiv(n, d, d^3<=n);

(PARI) N=99; x='x+O('x^N); Vec(sum(k=1, N^(1/3), x^k^3/(1-x^k)))

CROSSREFS

Cf. A000005, A010057, A038548, A347517.

Sequence in context: A348998 A167967 A160990 * A322357 A160989 A066788

Adjacent sequences:  A347513 A347514 A347515 * A347517 A347518 A347519

KEYWORD

nonn

AUTHOR

Seiichi Manyama, Sep 04 2021

STATUS

approved

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Last modified January 26 13:09 EST 2022. Contains 350598 sequences. (Running on oeis4.)