Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A002807
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A002807 Sum_{k=3..n} (k-1)!*C(n,k)/2.
(Formerly M4420 N1867)
+0
6
0, 0, 0, 1, 7, 37, 197, 1172, 8018, 62814, 556014, 5488059, 59740609, 710771275, 9174170011, 127661752406, 1904975488436, 30341995265036, 513771331467372, 9215499383109573, 174548332364311563, 3481204991988351553, 72920994844093191553, 1600596371590399671784 (list; graph; listen)
OFFSET

0,5

COMMENT

Maximal number of cycles in complete graph on n nodes. - Erich Friedman (erich.friedman(AT)stetson.edu).

REFERENCES

J. P. Char, Master circuit matrix, Proc. IEE, 115 (1968), 762-770.

F. C. Holroyd and W. J. G. Wingate, Cycles in the complement of a tree or other graph, Discrete Math., 55 (1985), 267-282.

LINKS

T. D. Noe, Table of n, a(n) for n=0..100

P. Pollack, Analytic and Combinatorial Number Theory Course Notes, ch. 7.

Eric Weisstein's World of Mathematics, Complete Graph

Eric Weisstein's World of Mathematics, Graph Cycle

FORMULA

E.g.f.: (-1/4)*exp(x)*(2*ln(1-x)+2*x+x^2). - Vladeta Jovovic (vladeta(AT)Eunet.yu), Oct 26 2004

a(n)=(n-1)*(n-2)/2+n*a(n-1)-(n-1)*a(n-2). - Vladeta Jovovic (vladeta(AT)Eunet.yu), Jan 22 2005

CROSSREFS

Cf. A117130, A099198, A099201, A070968.

Sequence in context: A085640 A069378 A117130 this_sequence A124610 A002683 A126475

Adjacent sequences: A002804 A002805 A002806 this_sequence A002808 A002809 A002810

KEYWORD

nonn,easy,nice

AUTHOR

njas

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 September 6 09:40 EDT 2008. Contains 143480 sequences.


AT&T Labs Research