login
A347527
Partial sums of A347526.
2
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
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
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Sep 05 2021
STATUS
approved