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A363407
Sum of divisors of 4*n-3 of form 4*k+3.
0
0, 0, 3, 0, 0, 10, 0, 0, 14, 0, 0, 18, 7, 0, 22, 0, 0, 26, 0, 18, 30, 0, 0, 34, 0, 0, 60, 0, 0, 42, 11, 0, 46, 26, 0, 50, 0, 0, 54, 0, 30, 84, 0, 0, 62, 0, 0, 100, 0, 0, 70, 0, 30, 74, 38, 0, 93, 0, 0, 82, 0, 42, 86, 34, 0, 90, 0, 0, 140, 0, 0, 132, 0, 0, 140, 50, 0, 106, 0, 0, 110, 0, 54, 114, 0, 42, 156
OFFSET
1,3
FORMULA
a(n) = A050452(4*n-3).
G.f.: Sum_{k>0} (4*k-1) * x^(3*k) / (1 - x^(4*k-1)).
MATHEMATICA
a[n_] := DivisorSum[4*n - 3, # &, Mod[#, 4] == 3 &]; Array[a, 100] (* Amiram Eldar, Jul 08 2023 *)
PROG
(PARI) a(n) = sumdiv(4*n-3, d, (d%4==3)*d);
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Jul 08 2023
STATUS
approved