A363033 Sum of divisors of 5*n-1 of form 5*k+3.

0, 3, 0, 0, 11, 0, 0, 16, 0, 0, 21, 0, 8, 26, 0, 0, 31, 0, 0, 36, 21, 0, 41, 0, 0, 46, 0, 0, 77, 0, 0, 56, 0, 13, 61, 0, 31, 66, 0, 0, 71, 0, 0, 76, 36, 0, 112, 0, 0, 86, 0, 0, 132, 0, 0, 96, 0, 0, 101, 36, 46, 106, 0, 0, 129, 0, 0, 116, 51, 0, 121, 0, 41, 126, 0, 0, 187, 0, 0, 136, 0, 0, 182, 0, 61, 192, 0, 0

Offset

1,2

Links

Table of n, a(n) for n=1..88.

Formula

a(n) = A284281(5*n-1).

G.f.: Sum_{k>0} (5*k-2) * x^(3*k-1) / (1 - x^(5*k-2)).

Mathematica

a[n_] := DivisorSum[5*n - 1, # &, Mod[#, 5] == 3 &]; Array[a, 100] (* Amiram Eldar, Jul 06 2023 *)

Prog

(PARI) a(n) = sumdiv(5*n-1, d, (d%5==3)*d);

Crossrefs

Cf. A363034, A363035, A363053.

Cf. A284281, A359288, A363155.

Sequence in context: A342312 A123474 A370064 * A321711 A277788 A208848

Adjacent sequences: A363030 A363031 A363032 * A363034 A363035 A363036

Keyword

nonn

Author

Seiichi Manyama, Jul 06 2023

Status

approved