A181203 a(n)=0!*1!*2!*3!*4!*(5*n)!*10*n*(n-1) / ((n)!*(n+1)!*(n+2)!*(n+3)!*(n+4)!)

0, 840, 360360, 199536480, 140229804000, 118949931243000, 117015012361447200, 129624266420759510400, 158211402715245473193600, 209298196564031904834960000, 296336346592302886974184080000

Offset

1,2

Comments

(Empirical) Number of nX5 matrices containing a defective permutation of 1..5*n in strictly increasing order rowwise and columnwise, with one permutation value omitted and one repeated (see example)

Column 5 of A181204

Links

R. H. Hardin, Table of n, a(n) for n=1..50

Example

Some solutions for 2X5
..1..4..5..6..8....1..2..4..7..9....1..3..5..8..9....1..2..5..6..8
..3..5..7..9.10....5..6..8..9.10....4..6..7..9.10....3..4..8..9.10

Crossrefs

Sequence in context: A055353 A107516 A091035 * A091036 A091038 A121498

Adjacent sequences: A181200 A181201 A181202 * A181204 A181205 A181206

Keyword

nonn

Author

R. H. Hardin Oct 10 2010

Status

approved