A347527 Partial sums of A347526.

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 17, 18, 20, 21, 23, 24, 26, 27, 29, 30, 32, 33, 35, 36, 38, 39, 41, 42, 44, 45, 47, 48, 50, 51, 53, 54, 56, 57, 59, 60, 62, 63, 65, 66, 68, 69, 71, 72, 74, 75, 77, 78, 80, 81, 83, 84, 86, 87, 89, 90, 92, 93, 95, 96, 98, 99, 101, 102

Offset: 1

Author

Seiichi Manyama, Sep 05 2021

Keywords

• nonn

Links

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

Crossrefs

Cf. A006218, A013938, A094820, A347517, A347526.

Programs

Mathematica

f[n_] := DivisorSum[n, 1 &, # <= n^(1/4) &]; Accumulate @ Array[f, 100] (* Amiram Eldar, Sep 05 2021 *)

PARI

a(n) = sum(k=1, n, sumdiv(k, d, d^4<=k));

PARI

N=99; x='x+O('x^N); Vec(sum(k=1, N^(1/4), x^k^4/(1-x^k))/(1-x))

Formula

G.f.: (1/(1 - x)) * Sum_{k>=1} x^(k^4)/(1 - x^k).