|
Search: id:A001052
|
|
|
| A001052 |
|
a(n) = n(n-1)a(n-1)/2 + a(n-2).
(Formerly M0911 N0343)
|
|
+0
2
|
|
| 1, 2, 3, 11, 69, 701, 10584, 222965, 6253604, 225352709, 10147125509, 558317255704, 36859086001973, 2875567025409598, 261713458398275391, 27482788698844325653, 3298196357319717353751, 448582187384180404435789
(list; graph; listen)
|
|
|
OFFSET
|
0,2
|
|
|
REFERENCES
|
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
|
|
PROGRAM
|
(PARI) a(n)=if(n<2, max(0, n+1), n*(n-1)*a(n-1)/2+a(n-2))
|
|
CROSSREFS
|
Sequence in context: A105217 A066046 A065597 this_sequence A155187 A109132 A008510
Adjacent sequences: A001049 A001050 A001051 this_sequence A001053 A001054 A001055
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
N. J. A. Sloane (njas(AT)research.att.com).
|
|
EXTENSIONS
|
More terms from James A. Sellers (sellersj(AT)math.psu.edu), Sep 19 2000
|
|
|
Search completed in 0.002 seconds
|
