|
| |
|
|
A006333
|
|
From the enumeration of corners.
(Formerly M2175)
|
|
0
| |
|
|
0, 2, 60, 660, 4290, 20020, 74256, 232560, 639540, 1586310, 3617900, 7696260, 15438150, 29451240, 53796160, 94607040, 160908264, 265670730, 427156860, 670609940, 1030350090, 1552346268, 2297341200, 3344614000, 4796473500
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
REFERENCES
| G. Kreweras, Sur une classe de problemes de denombrement lies au treillis des partitions des entiers, Cahiers du Bureau Universitaire de Recherche Op\'{e}rationnelle}, Institut de Statistique, Universit\'{e} de Paris, 6 (1965), circa p. 82.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
|
|
|
FORMULA
| a(n) = (n*(1 + n)^2*(2 + n)^2*(3 + n)*(1 + 2*n)*(3 + 2*n)*(5 + 2*n))/7560.
G.f.: 2*(1+20*x+75*x^2+75*x^3+20*x^4+x^5)/(1-x)^10.
|
|
|
CROSSREFS
| A row of A132339.
Sequence in context: A067739 A187626 A059934 * A001760 A157059 A199643
Adjacent sequences: A006330 A006331 A006332 * A006334 A006335 A006336
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
|
| |
|
|
