A364102 Sum of divisors of 5*n-3 of form 5*k+4.

0, 0, 4, 0, 0, 9, 4, 0, 14, 0, 4, 19, 0, 0, 37, 0, 0, 29, 4, 0, 34, 0, 18, 48, 0, 0, 48, 0, 0, 49, 23, 0, 63, 0, 4, 59, 14, 0, 92, 0, 0, 78, 4, 0, 74, 0, 33, 79, 0, 19, 111, 0, 0, 89, 38, 0, 94, 0, 4, 108, 0, 0, 171, 0, 14, 109, 4, 0, 142, 0, 48, 119, 0, 0, 128, 29, 0, 138, 67, 0, 134, 0, 4, 139, 0, 0

Offset

1,3

Links

Table of n, a(n) for n=1..86.

Formula

a(n) = A284103(5*n-3).

G.f.: Sum_{k>0} (5*k-1) * x^(3*k) / (1 - x^(5*k-1)).

Mathematica

a[n_] := DivisorSum[5*n - 3, # &, Mod[#, 5] == 4 &]; Array[a, 100] (* Amiram Eldar, Jul 17 2023 *)

Prog

(PARI) a(n) = sumdiv(5*n-3, d, (d%5==4)*d);

Crossrefs

Cf. A364100, A364101, A364103.

Cf. A284103, A359270, A364106.

Sequence in context: A002915 A127733 A330379 * A249035 A244121 A127774

Adjacent sequences: A364099 A364100 A364101 * A364103 A364104 A364105

Keyword

nonn

Author

Seiichi Manyama, Jul 04 2023

Status

approved