The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A108188 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A108188

a(n) = (n-1)*(a(n-1)+a(n-2)+a(n-3)).
(history; published version)

#4 by Harvey P. Dale at Sat Oct 26 11:00:07 EDT 2019

STATUS

editing

approved

#3 by Harvey P. Dale at Sat Oct 26 11:00:04 EDT 2019

MATHEMATICA

RecurrenceTable[{a[1]==0, a[2]==a[3]==1, a[n]==(n-1)(a[n-1]+a[n-2]+a[n-3])}, a, {n, 20}] (* Harvey P. Dale, Oct 26 2019 *)

STATUS

approved

editing

#2 by Russ Cox at Fri Mar 30 17:34:19 EDT 2012

AUTHOR

_Roger L. Bagula (rlbagulatftn(AT)yahoo.com), _, Jun 14 2005

Discussion

Fri Mar 30

17:34

OEIS Server: https://oeis.org/edit/global/158

#1 by N. J. A. Sloane at Tue Jul 19 03:00:00 EDT 2005

NAME

a(n) = (n-1)*(a(n-1)+a(n-2)+a(n-3)).

DATA

0, 1, 1, 6, 32, 195, 1398, 11375, 103744, 1048653, 11637720, 140691287, 1840531920, 25907192051, 390437813612, 6272783063745, 107026049110528, 1932717589794045, 36828295595429724, 738492745452351643

OFFSET

1,4

COMMENTS

Derangement-type sequence like A000166 on the tribonacci A000213.

MATHEMATICA

F[1] = 0; F[2] = 1; F[3] = 1; F[n__] := F[n] = (n - 1)*(F[n - 1] + F[n - 2] + F[n - 3]) a = Table[F[n], {n, 1, 25}]

CROSSREFS

Cf. A000166, A000213.

KEYWORD

nonn

AUTHOR

Roger L. Bagula (rlbagulatftn(AT)yahoo.com), Jun 14 2005

STATUS

approved