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A277741
Symmetric array read by antidiagonals: T(n,k) (n >= 1, k >= 1) = number of multiquadrangulations of the sphere with n stable equilibria and k unstable equilibria.
0
1, 1, 1, 1, 2, 1, 2, 5, 5, 2, 3, 13, 20, 13, 3, 6, 35, 83, 83, 35, 6, 12, 104, 340, 504, 340, 12, 27, 315, 1401, 2843, 2843, 1401, 316, 27, 65, 1021, 5809, 15578, 21420, 15578, 5809, 1021, 65
OFFSET
1,5
LINKS
Richard Kapolnai, Gabor Domokos, and Timea Szabo, Generating spherical multiquadrangulations by restricted vertex splittings and the reducibility of equilibrium classes Periodica Polytechnica Electrical Engineering, 56(1):11-10, 2012. Also arXiv:1206.1698 [cs.DM], 2012. See Table 1.
EXAMPLE
The array begins:
1, 1, 1, 2, 3, 6, 12, 27, 65, ...
1, 2, 5, 13, 35, 104, 315, 1021, ...
1, 5, 20, 83, 340, 1401, 5809, ...
2, 13, 83, 504, 2843, 15578, ...
3, 35, 340, 2843, 21420, ...
6, 104, 1401, 15578, ...
12, 315, 5809, ...
27, 1021, ...
65, ...
...
CROSSREFS
Row 2 (equally, column 2) is A006082.
Sequence in context: A143913 A228815 A241555 * A241138 A241349 A330405
KEYWORD
nonn,tabl,more
AUTHOR
N. J. A. Sloane, Nov 07 2016
STATUS
approved