

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
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OFFSET

1,2


REFERENCES

F. Bergeron, G. Labelle and P. Leroux, Combinatorial Species and TreeLike Structures, Cambridge, 1998, pg 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((1x*y)^2/(1x*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: A117270 A244137 A181389 * A134085 A151339 A228273
Adjacent sequences: A091463 A091464 A091465 * A091467 A091468 A091469


KEYWORD

nonn,tabl


AUTHOR

Christian G. Bower, Jan 12 2004


STATUS

approved



