The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A178989 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A178989

a(n) = (k^k + k!) / (k*(k + 1)), where k = prime(n) - 1.
(history; published version)

#20 by Alois P. Heinz at Tue Apr 13 19:21:57 EDT 2021

STATUS

editing

approved

#19 by Alois P. Heinz at Tue Apr 13 19:21:53 EDT 2021

CROSSREFS

Cf. A000040.

STATUS

approved

editing

#18 by Alois P. Heinz at Tue Apr 13 19:13:36 EDT 2021

STATUS

proposed

approved

#17 by Andrew Howroyd at Tue Apr 13 19:07:04 EDT 2021

STATUS

editing

proposed

#16 by Andrew Howroyd at Tue Apr 13 19:06:39 EDT 2021

NAME

a(n) = (k^k + k!) / (k*(k + 1), ), where k = prime(n) - 1.

DATA

1, 1, 14, 1128, 90942080, 57157560576, 67818988957718528, 115047995548743401472, 674758653138775267142795264, 40819609745761407890621234130376982528, 221388314080552960064314183934017536000000, 79870389582370042643423622863118514819531536385179648

LINKS

Andrew Howroyd, <a href="/A178989/b178989.txt">Table of n, a(n) for n = 1..50</a>

PROG

(PARI) a(n)={my(k=prime(n)-1); (k^k + k!) / (k*(k + 1))} \\ Andrew Howroyd, Apr 13 2021

EXTENSIONS

Terms a(11) and beyond from Andrew Howroyd, Apr 13 2021

STATUS

approved

editing

#15 by Jon E. Schoenfield at Sat Mar 14 15:44:31 EDT 2015

STATUS

editing

approved

#14 by Jon E. Schoenfield at Sat Mar 14 15:44:26 EDT 2015

MATHEMATICA

f[n_] := Block[{k = Prime@ n - 1}, (k^k + k!)/(k (k + 1))]; Array[f, 10] (* _Robert G. Wilson_ v, _, Jan 05 2011 *)

STATUS

approved

editing

#13 by Jon E. Schoenfield at Sat Mar 14 15:44:05 EDT 2015

STATUS

editing

approved

#12 by Jon E. Schoenfield at Sat Mar 14 15:44:03 EDT 2015

MATHEMATICA

f[n_] := Block[{k = Prime@ n - 1}, (k^k + k!)/(k (k + 1))]; Array[f, 10] (* Robert G. Wilson, v, Jan 05 2011 *)

STATUS

approved

editing

#11 by Charles R Greathouse IV at Thu Nov 21 13:14:50 EST 2013

MATHEMATICA

f[n_] := Block[{k = Prime@ n - 1}, (k^k + k!)/(k (k + 1))]; Array[f, 10] (* From _Robert G. Wilson, _, Jan 05 2011 *)

Discussion

Thu Nov 21

13:14

OEIS Server: https://oeis.org/edit/global/2069