cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A181204 T(n,k) = 0!*1!*2!*...*(k-1)! *(n*k)! *k*(k-1)*n*(n-1) / 2*n!*(n+1)!*...*(n+k-1)!

Original entry on oeis.org

0, 0, 0, 0, 4, 0, 0, 30, 30, 0, 0, 168, 756, 168, 0, 0, 840, 16632, 16632, 840, 0, 0, 3960, 360360, 1729728, 360360, 3960, 0, 0, 18018, 7876440, 199536480, 199536480, 7876440, 18018, 0, 0, 80080, 174594420, 25241364720, 140229804000, 25241364720
Offset: 1

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Author

R. H. Hardin Oct 10 2010

Keywords

Comments

(Empricial) T(n,k)=Number of nXk matrices containing a defective permutation of 1..n*k in strictly increasing order rowwise and columnwise, with one permutation value omitted and one repeated (see example)
Formula is n*(n-1)*k*(k-1)/2 times n-th k-dimensional Catalan number
Table starts
.0.......0.............0....................0...........................0
.0.......4............30..................168.........................840
.0......30...........756................16632......................360360
.0.....168.........16632..............1729728...................199536480
.0.....840........360360............199536480................140229804000
.0....3960.......7876440..........25241364720.............118949931243000
.0...18018.....174594420........3445446284280..........117015012361447200
.0...80080....3926434512......500598983364480.......129624266420759510400
.0..350064...89492111280....76591644454765440....158211402715245473193600
.0.1511640.2064420294300.12237255920840932800.209298196564031904834960000

Examples

			Some solutions for 4X2
..2..4....1..4....1..3....1..3....2..5....1..3....1..3....2..4....1..2....1..3
..3..5....2..5....3..6....2..4....3..6....2..4....2..4....3..6....2..4....2..4
..5..7....6..7....4..7....4..6....4..7....4..5....4..7....5..7....3..5....4..7
..6..8....7..8....5..8....5..8....5..8....7..8....5..8....6..8....6..8....6..8
		

Crossrefs

Column 2 is twice A002740(n+1)
Cf. A060854 for permutation without defect.