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A091467
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Table (by antidiagonals) of unlabeled alternating octupi with n black nodes and k white nodes.
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3
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1, 1, 1, 0, 4, 0, 0, 3, 3, 0, 0, 1, 10, 1, 0, 0, 0, 9, 9, 0, 0, 0, 0, 3, 28, 3, 0, 0, 0, 0, 1, 28, 28, 1, 0, 0, 0, 0, 0, 15, 76, 15, 0, 0, 0, 0, 0, 0, 3, 90, 90, 3, 0, 0, 0, 0, 0, 0, 1, 55, 238, 55, 1, 0, 0, 0, 0, 0, 0, 0, 18, 297, 297, 18, 0, 0, 0, 0, 0, 0, 0, 0, 3, 219, 736, 219, 3, 0, 0, 0, 0, 0
(list; table; graph; refs; listen; history; internal format)
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OFFSET
| 1,5
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REFERENCES
| F. Bergeron, G. Labelle and P. Leroux, Combinatorial Species and Tree-Like Structures, Cambridge, 1998, pg 113 (2.4.41)
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FORMULA
| G.f.: A(x, y) = Sum_{k>=1} (phi(k)/k)*log((1-x^n*y^n)^2/(1-x^n*y^n*(3+x^n+y^n))).
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EXAMPLE
| 1 1 0 0 0 ...
1 4 3 1 0 ...
0 3 10 9 3 ...
0 1 9 28 28 ...
0 0 3 28 76 ...
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CROSSREFS
| Main diagonal: A091468. Row sums: A091468. Cf. A091466.
Sequence in context: A193717 A020808 A198364 * A050443 A036480 A035639
Adjacent sequences: A091464 A091465 A091466 * A091468 A091469 A091470
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KEYWORD
| nonn,tabl
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AUTHOR
| Christian G. Bower (bowerc(AT)usa.net), Jan 12 2004
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