|
Search: id:A000426
|
|
|
| A000426 |
|
Coefficients of menage hit polynomials.
(Formerly M4515 N1910)
|
|
+0
3
|
|
| 0, 1, 1, 1, 8, 35, 211, 1459, 11584, 103605, 1030805, 11291237, 135015896, 1749915271, 24435107047, 365696282855, 5839492221440, 99096354764009, 1780930394412009, 33789956266629001, 674939337282352360, 14157377139256183723
(list; graph; listen)
|
|
|
OFFSET
|
1,5
|
|
|
REFERENCES
|
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, p. 198.
H. M. Taylor, A problem on arrangements, Mess. Math., 32 (1902), 60ff.
|
|
LINKS
|
David W. Wilson, Table of n, a(n) for n = 1..100
|
|
FORMULA
|
a(n) = SUM(k = 2..n, ((-1)^k (2n-k-1)! (n-k)!)/((2n-2k)! (k-2)!))
a(n) = A000033(n)/n.
|
|
MAPLE
|
a(n) = ((2n-5)a(n-1) + (5n-11)a(n-2) + (5n-14)a(n-3) + (2n-5)a(n-4) + 2a(n-5))/2 for n >= 6.
|
|
CROSSREFS
|
Cf. A000179, A000271. A diagonal of A058057.
Sequence in context: A094616 A114569 A098999 this_sequence A089698 A133887 A057345
Adjacent sequences: A000423 A000424 A000425 this_sequence A000427 A000428 A000429
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
N. J. A. Sloane (njas(AT)research.att.com) and Simon Plouffe (simon.plouffe(AT)gmail.com)
|
|
EXTENSIONS
|
Edited by David W. Wilson, Dec 27 2007
|
|
|
Search completed in 0.002 seconds
|
