A363317 Sum of divisors of 4*n-3 of form 4*k+1.

1, 6, 10, 14, 18, 22, 31, 30, 34, 38, 42, 60, 50, 54, 58, 62, 84, 70, 74, 78, 91, 108, 90, 94, 98, 102, 132, 110, 114, 140, 122, 156, 130, 134, 138, 142, 180, 150, 180, 158, 162, 204, 183, 174, 178, 182, 228, 220, 194, 198, 202, 252, 210, 214, 218, 252, 310, 230, 234, 238, 242, 300, 250, 254, 258, 300, 324

Offset

1,2

Links

Table of n, a(n) for n=1..67.

Formula

a(n) = A050449(4*n-3).

G.f.: Sum_{k>0} (4*k-3) * x^k / (1 - x^(4*k-3)).

Mathematica

a[n_] := DivisorSum[4*n - 3, # &, Mod[#, 4] == 1 &]; Array[a, 100] (* Amiram Eldar, Jul 08 2023 *)

Prog

(PARI) a(n) = sumdiv(4*n-3, d, (d%4==1)*d);

Crossrefs

Cf. A050449, A359227, A364083.

Sequence in context: A187682 A315180 A243709 * A315181 A315182 A315183

Adjacent sequences: A363314 A363315 A363316 * A363318 A363319 A363320

Keyword

nonn

Author

Seiichi Manyama, Jul 08 2023

Status

approved