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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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..36.

V. Pilaud, J. Rué, Analytic combinatorics of chord and hyperchord diagrams with k crossings, arXiv preprint arXiv:1307.6440, 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: A238008 A193547 A144481 * A200126 A065469 A249522

Adjacent sequences:  A232222 A232223 A232224 * A232226 A232227 A232228

KEYWORD

nonn,tabf,more

AUTHOR

N. J. A. Sloane, Nov 22 2013

STATUS

approved

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Last modified March 24 00:12 EDT 2019. Contains 321444 sequences. (Running on oeis4.)