The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A052662

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A052662

E.g.f. (1-x^2)/(1-2x-x^2+x^3).
(history; published version)

#15 by Harvey P. Dale at Sun Jan 29 15:31:11 EST 2023

STATUS

editing

approved

#14 by Harvey P. Dale at Sun Jan 29 15:31:08 EST 2023

MATHEMATICA

With[{nn=20}, CoefficientList[Series[(1-x^2)/(1-2x-x^2+x^3), {x, 0, nn}], x] Range[ 0, nn]!] (* Harvey P. Dale, Jan 29 2023 *)

STATUS

approved

editing

#13 by N. J. A. Sloane at Tue Apr 18 07:03:59 EDT 2017

LINKS

INRIA Algorithms Project, <a href="http://algoecs.inria.fr/ecsservices/ecsstructure?searchType=1&service=Search&searchTermsnbr=609">Encyclopedia of Combinatorial Structures 609</a>

Discussion

Tue Apr 18

07:03

OEIS Server: https://oeis.org/edit/global/2632

#12 by Jon E. Schoenfield at Wed Dec 21 23:27:16 EST 2016

STATUS

editing

approved

#11 by Jon E. Schoenfield at Wed Dec 21 23:27:14 EST 2016

FORMULA

a(n) = n!*A052534(n). - _R. J. Mathar, _, Nov 27 2011

STATUS

approved

editing

#10 by Charles R Greathouse IV at Thu Dec 01 11:32:08 EST 2011

LINKS

INRIA Algorithms Project, <a href="http://algo.inria.fr/binecs/encyclopediaecs?searchType=1&service=Search=ECSnb&argsearchsearchTerms=609">Encyclopedia of Combinatorial Structures 609</a>

Discussion

Thu Dec 01

11:32

OEIS Server: https://oeis.org/edit/global/103

#9 by R. J. Mathar at Sun Nov 27 10:53:53 EST 2011

STATUS

editing

approved

#8 by R. J. Mathar at Sun Nov 27 10:53:46 EST 2011

NAME

A simple regular expression in a labeled universe.

E.g.f. (1-x^2)/(1-2x-x^2+x^3).

FORMULA

Recurrence: {a(0)=1, a(1)=2, a(2)=8, (n^3+6*n^2+11*n+6)*a(n)+(-n^2-5*n-6)*a(n+1)+(-2*n-6)*a(n+2)+a(n+3)=0}

a(n) = n!*A052534(n). - R. J. Mathar, Nov 27 2011

STATUS

approved

editing

#7 by N. J. A. Sloane at Thu Nov 11 07:34:06 EST 2010

LINKS

INRIA Algorithms Project, <a href="http://algo.inria.fr/bin/encyclopedia?Search=ECSnb&argsearch=609">Encyclopedia of Combinatorial Structures 609</a>

KEYWORD

easy,nonn,new

#6 by N. J. A. Sloane at Fri Feb 24 03:00:00 EST 2006

FORMULA

Recurrence: {a(0)=1, a(1)=2, a(2)=8, (n^3+6*n^2+11*n+6)*a(n)+(-n^2-5*n-6)*a(n+1)+(-2*n-6)*a(n+2)+a(n+3)}

Sum(1/7*(2+_alpha)*_alpha^(-1-n),_ _alpha=RootOf(_Z^3-_Z^2-2*_Z+1))*n!

KEYWORD

easy,nonn,new