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, 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).

Links

Table of n, a(n) for n=1..60.

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

Cf. A029767, A091467.

Sequence in context: A354127 A181389 A369072 * A134085 A151339 A228273

Adjacent sequences: A091463 A091464 A091465 * A091467 A091468 A091469

Keyword

nonn,tabl

Author

Christian G. Bower, Jan 12 2004

Status

approved