login
A363033
Sum of divisors of 5*n-1 of form 5*k+3.
4
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
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
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Jul 06 2023
STATUS
approved