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A232227 Triangle read by rows: T(n,k) = number of crossing connected diagrams in a disk having n crossings and k chords. 2
1, 0, 8, 0, 1, 82, 0, 0, 43, 868, 0, 0, 11, 920, 9726, 0, 0, 1, 590, 15524, 113536, 0, 0, 0, 243, 15904, 243040, 1366570 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..28.

V. Pilaud, J. Rué, Analytic combinatorics of chord and hyperchord diagrams with k crossings, arXiv preprint arXiv:1307.6440, 2013

EXAMPLE

Triangle begins:

1,

0,8,

0,1,82,

0,0,43,868,

0,0,11,920,9726,

0,0,1,590,15524,113536,

0,0,0,243,15904,243040,1366570,

...

CROSSREFS

Cf. A232226 (row sums), A232225.

Sequence in context: A195447 A160389 A011104 * A322231 A261168 A329086

Adjacent sequences:  A232224 A232225 A232226 * A232228 A232229 A232230

KEYWORD

nonn,tabl,more

AUTHOR

N. J. A. Sloane, Nov 22 2013

STATUS

approved

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Last modified December 5 10:45 EST 2019. Contains 329751 sequences. (Running on oeis4.)