Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A091106
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A091106 a(0)=a(1)=-1. For n>1: a(n)=Sum(i!i^2 Stirling2[n-1,i],i=2,..,n-1). +0
2
-1, -1, 0, 8, 78, 764, 8310, 100988, 1362438, 20246444, 328972470, 5805917468, 110645911398, 2265191981324, 49589790516630, 1156201277261948, 28605950745797958, 748605590542359404, 20661245832389468790, 599820758571599742428, 18272940402442730318118 (list; graph; listen)
OFFSET

0,4

FORMULA

E.g.f.: (exp(x)-1)^2/(2(exp(x)-2)^2)-exp(x). a(n)=(1/2)(A069321(n)-A000670(n))-1.

MATHEMATICA

CoefficientList[Series[(1/2)((Exp[x]-1)/(Exp[x]-2))^2-Exp[x], {x, 0, 20}], x]

CROSSREFS

Sequence in context: A092661 A074841 A136954 this_sequence A111533 A132164 A058480

Adjacent sequences: A091103 A091104 A091105 this_sequence A091107 A091108 A091109

KEYWORD

easy,sign

AUTHOR

Mario Catalani (mario.catalani(AT)unito.it), Dec 19 2003

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified December 3 16:57 EST 2008. Contains 151279 sequences.


AT&T Labs Research