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A232225
Irregular triangle read by rows: T(n,k) = number of crossing connected diagrams in a disk having n crossings and k vertices.
2
1, 0, 5, 3, 0, 5, 31, 35, 12, 0, 0, 54, 231, 346, 225, 55, 0, 1, 51, 532, 1942, 3366, 3062, 1430, 273, 0, 0, 39, 784, 5253, 17631, 33300, 37312, 24804, 9100, 1428
OFFSET
1,3
LINKS
V. Pilaud and J. Rué, Analytic combinatorics of chord and hyperchord diagrams with k crossings, arXiv preprint arXiv:1307.6440 [math.CO], 2013.
EXAMPLE
Triangle begins:
1;
0, 5, 3;
0, 5, 31, 35, 12;
0, 0, 54, 231, 346, 225, 55;
0, 1, 51, 532, 1942, 3366, 3062, 1430, 273;
0, 0, 39, 784, 5253, 17631, 33300, 37312, 24804, 9100, 1428;
...
CROSSREFS
Cf. A232226 (row sums), A232227.
Sequence in context: A144481 A374172 A350550 * A365075 A200126 A065469
KEYWORD
nonn,tabf,more
AUTHOR
N. J. A. Sloane, Nov 22 2013
STATUS
approved