The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A363053 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A363053

Sum of divisors of 5*n-4 of form 5*k+3.
(history; published version)

#30 by Michel Marcus at Thu Jul 06 07:30:36 EDT 2023

STATUS

reviewed

approved

#29 by Joerg Arndt at Thu Jul 06 06:00:39 EDT 2023

STATUS

proposed

reviewed

#28 by Amiram Eldar at Thu Jul 06 06:00:20 EDT 2023

STATUS

editing

proposed

#27 by Amiram Eldar at Thu Jul 06 06:00:18 EDT 2023

MATHEMATICA

a[n_] := DivisorSum[5*n - 4, # &, Mod[#, 5] == 3 &]; Array[a, 100] (* Amiram Eldar, Jul 06 2023 *)

STATUS

proposed

editing

#26 by Seiichi Manyama at Thu Jul 06 04:45:28 EDT 2023

STATUS

editing

proposed

#25 by Seiichi Manyama at Thu Jul 06 01:49:52 EDT 2023

CROSSREFS

Cf. A284281, A359244, A363158.

#24 by Seiichi Manyama at Thu Jul 06 01:28:25 EDT 2023

PROG

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

#23 by Seiichi Manyama at Thu Jul 06 01:26:29 EDT 2023

DATA

0, 3, 0, 8, 3, 13, 0, 21, 0, 23, 3, 36, 0, 36, 0, 38, 3, 43, 13, 59, 0, 53, 3, 58, 0, 84, 0, 76, 3, 73, 0, 94, 23, 83, 3, 96, 0, 96, 0, 126, 3, 103, 0, 137, 13, 113, 36, 118, 0, 126, 0, 136, 3, 171, 0, 164, 0, 156, 3, 156, 43, 174, 0, 158, 3, 163, 0, 255, 0, 173, 16, 178, 0, 186, 53, 196, 3, 193, 23, 252

#22 by Seiichi Manyama at Thu Jul 06 01:26:04 EDT 2023

FORMULA

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

#21 by Seiichi Manyama at Thu Jul 06 01:22:05 EDT 2023

FORMULA

a(n) = A284281(5*n-4).