A212930 T(n,k) = number of n X k 0..k-1 arrays with no column j greater than column j-1 in all rows.
1, 3, 1, 10, 15, 1, 35, 568, 63, 1, 126, 39695, 18226, 255, 1, 462, 4431876, 14177855, 518320, 1023, 1, 1716, 724082352, 23124921876, 4041974015, 14230810, 4095, 1, 6435, 163050236504, 68264066143602, 85800824609376, 1075113010175, 386357608
Offset: 1
Examples
Some solutions for n=3 k=4 ..2..0..1..0....1..0..0..0....3..1..1..1....1..0..2..3....2..2..1..0 ..2..0..1..2....0..3..1..2....3..2..3..0....2..1..1..0....0..3..0..0 ..1..3..0..0....1..0..1..3....1..1..1..1....3..3..0..1....1..1..1..3
Links
- R. H. Hardin, Table of n, a(n) for n = 1..172
Formula
Empirical for column k:
k=1: a(n) = a(n-1)
k=2: a(n) = 5*a(n-1) -4*a(n-2)
k=3: a(n) = 37*a(n-1) -279*a(n-2) +243*a(n-3)
k=4: a(n) = 405*a(n-1) -43860*a(n-2) +1524160*a(n-3) -15636480*a(n-4) +14155776*a(n-5)
The coefficient of a(n-1) is A209671(k) (through at least k=1..7)
Comments