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A091466
Table (by antidiagonals) of labeled alternating octupi with n black nodes and k white nodes. Each type of object labeled from its own label set.
1
1, 2, 2, 0, 14, 0, 0, 36, 36, 0, 0, 24, 336, 24, 0, 0, 0, 1296, 1296, 0, 0, 0, 0, 2160, 14832, 2160, 0, 0, 0, 0, 1440, 80640, 80640, 1440, 0, 0, 0, 0, 0, 233280, 1082880, 233280, 0, 0, 0, 0, 0, 0, 362880, 7776000, 7776000, 362880, 0, 0, 0, 0, 0, 0, 241920, 33264000
OFFSET
1,2
REFERENCES
F. Bergeron, G. Labelle and P. Leroux, Combinatorial Species and Tree-Like Structures, Cambridge, 1998, p. 113 (2.4.41).
FORMULA
Double e.g.f.: A(x, y) = Sum_{i, j>=0} (x^i*y^j/(i!*j!)) = log((1-x*y)^2/(1-x*y*(3+x+y))).
EXAMPLE
1 2 0 0 0 ...
2 4 36 24 0 ...
0 36 336 1296 2160 ...
0 24 1296 14832 80640 ...
0 0 2160 80640 1082880 ...
CROSSREFS
Sequence in context: A354127 A181389 A369072 * A134085 A151339 A228273
KEYWORD
nonn,tabl
AUTHOR
Christian G. Bower, Jan 12 2004
STATUS
approved