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A181399 Summed lengths of nonintersecting rook paths on an n X k board (square array by antidiagonals). 6
0, 1, 1, 2, 4, 2, 3, 14, 14, 3, 4, 40, 64, 40, 4, 5, 104, 284, 284, 104, 5, 6, 256, 1206, 1912, 1206, 256, 6, 7, 608, 4882, 13132, 13132, 4882, 608, 7, 8, 1408, 19060, 88608, 148432, 88608, 19060, 1408, 8, 9, 3200, 72588, 577727, 1692480, 1692480, 577727, 72588, 3200, 9 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

Paths are self-avoiding from one corner to the diagonally opposite corner.

LINKS

David Scambler, Table of n, a(n) for n = 1..66

EXAMPLE

Array starts

======================================================

n\k| 1   2     3      4        5        6        7

---|--------------------------------------------------

1  | 0   1     2      3        4        5        6 ...

2  | 1   4    14     40      104      256      608 ...

3  | 2  14    64    284     1206     4882    19060 ...

4  | 3  40   284   1912    13132    88608   577727 ...

5  | 4 104  1206  13132   148432  1692480 18893254 ...

6  | 5 256  4882  88608  1692480 32871240 ...

7  | 6 608 19060 577727 18893254 ...

...

CROSSREFS

Related sequences: A181394 (3 X n), A181395 (4 X n), A181396 (5 X n), A181397 (6 X n), A181398 (n X n).

Sequence in context: A134400 A016095 A298309 * A253581 A165464 A308658

Adjacent sequences:  A181396 A181397 A181398 * A181400 A181401 A181402

KEYWORD

nonn,tabl

AUTHOR

David Scambler, Oct 17 2010

EXTENSIONS

a(55) and a(60) in b-file corrected by Andrew Howroyd, Feb 23 2018

STATUS

approved

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Last modified December 7 09:33 EST 2019. Contains 329843 sequences. (Running on oeis4.)