|
| |
|
|
A006152
|
|
Exponential generating function x*exp(x/(1-x)).
(Formerly M1939)
|
|
2
| |
|
|
1, 2, 9, 52, 365, 3006, 28357, 301064, 3549177, 45965530, 648352001, 9888877692, 162112109029, 2841669616982, 53025262866045, 1049180850990736, 21937381717388657, 483239096122434354, 11184035897992673017
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,2
|
|
|
REFERENCES
| Getu, S.; Shapiro, L. W.; Combinatorial view of the composition of functions. Ars Combin. 10 (1980), 131-145.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
|
|
|
LINKS
| INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 156
|
|
|
PROG
| (PARI) a(n)=n!*polcoeff(x*exp(x/(1-x)+O(x^n)), n)
|
|
|
CROSSREFS
| A006152(n)=n*A000262(n-1).
Sequence in context: A193465 A003584 A069271 * A143508 A052882 A143922
Adjacent sequences: A006149 A006150 A006151 * A006153 A006154 A006155
|
|
|
KEYWORD
| nonn,easy,changed
|
|
|
AUTHOR
| Simon Plouffe (simon.plouffe(AT)gmail.com)
|
|
|
EXTENSIONS
| More terms from Michael Somos, Jun 07 2000
|
| |
|
|
