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

1,2

Links

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

Formula

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

Mathematica

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

Prog

(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))

Crossrefs

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

Sequence in context: A191932 A044920 A330938 * A022766 A249611 A323035

Adjacent sequences: A347524 A347525 A347526 * A347528 A347529 A347530

Keyword

nonn

Author

Seiichi Manyama, Sep 05 2021

Status

approved