The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A358410 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A358410

a(n) = Sum_{d|n} (d + n/d - 2)!/(d - 1)!.
(history; published version)

#13 by Joerg Arndt at Wed Aug 30 02:00:56 EDT 2023

STATUS

reviewed

approved

#12 by Michel Marcus at Wed Aug 30 01:57:23 EDT 2023

STATUS

proposed

reviewed

#11 by Amiram Eldar at Wed Aug 30 00:13:47 EDT 2023

STATUS

editing

proposed

#10 by Amiram Eldar at Wed Aug 30 00:07:46 EDT 2023

MATHEMATICA

a[n_] := DivisorSum[n, (# + n/# - 2)!/(# - 1)! &]; Array[a, 23] (* Amiram Eldar, Aug 30 2023 *)

STATUS

approved

editing

#9 by Michel Marcus at Mon Nov 14 08:23:43 EST 2022

STATUS

reviewed

approved

#8 by Joerg Arndt at Mon Nov 14 07:43:33 EST 2022

STATUS

proposed

reviewed

#7 by Seiichi Manyama at Mon Nov 14 07:41:11 EST 2022

STATUS

editing

proposed

#6 by Seiichi Manyama at Mon Nov 14 07:21:22 EST 2022

CROSSREFS

Cf. A157019, A358280, A358389.

#5 by Seiichi Manyama at Mon Nov 14 07:04:48 EST 2022

FORMULA

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

If p is prime, a(p) = 1 + (p-1)!.

#4 by Seiichi Manyama at Mon Nov 14 07:02:36 EST 2022

DATA

1, 2, 3, 9, 25, 130, 721, 5069, 40333, 363006, 3628801, 39917607, 479001601, 6227025848, 87178291591, 1307674408449, 20922789888001, 355687428461452, 6402373705728001, 121645100412461861, 2432902008176660217, 51090942171749356812, 1124000727777607680001