A260043 Irregular triangle read by rows: T(n,k) (n >= 1, 0 <= k <= n^2) = number of n X n (0,1) real matrices with k zeros and permanent zero.

0, 1, 0, 0, 4, 4, 1, 0, 0, 0, 6, 45, 90, 78, 36, 9, 1, 0, 0, 0, 0, 8, 96, 576, 2128, 4860, 676, 6496, 4080, 1796, 560, 120, 16, 1, 0, 0, 0, 0, 0, 10, 200, 1900, 11500, 50025, 166720, 439600, 923700, 1534800, 1994200, 2010920, 1571525, 956775, 458500, 174700, 53010, 12650, 2300, 300, 25, 1

Offset

1,5

References

M. B. Wells, Elements of Combinatorial Computing. Pergamon, Oxford, 1971, see p. 240.

Links

Table of n, a(n) for n=1..60.

M. B. Wells, Elements of Combinatorial Computing, Pergamon, Oxford, 1971. [Annotated scanned copy of pages 237-240]

Example

Triangle begins:
0,1,
0,0,4,4,1,
0,0,0,6,45,90,78,36,9,1,
0,0,0,0,8,96,576,2128,4860,676,6496,4080,1796,560,120,16,1,
0,0,0,0,0,10,200,1900,11500,50025,166720,439600,923700,1534800,1994200,2010920,1571525,956775,458500,174700,53010,12650,2300,300,25,1,
...

Crossrefs

Sequence in context: A350491 A365957 A365954 * A366467 A366464 A185057

Adjacent sequences: A260040 A260041 A260042 * A260044 A260045 A260046

Keyword

nonn,tabf

Author

N. J. A. Sloane, Jul 22 2015

Status

approved