A264878 T(n,k)=Number of (n+1)X(k+1) arrays of permutations of 0..(n+1)*(k+1)-1 with each element having directed index change 0,1 0,-1 -2,0 or 1,1.
1, 0, 1, 1, 0, 1, 0, 1, 0, 2, 1, 1, 5, 0, 3, 0, 7, 4, 20, 0, 4, 1, 20, 65, 12, 56, 0, 5, 0, 49, 228, 572, 36, 137, 0, 6, 1, 175, 1101, 2348, 3613, 108, 295, 0, 8, 0, 323, 4832, 22152, 22400, 19372, 324, 709, 0, 11, 1, 1085, 18501, 129230, 356692, 207424, 103585, 972, 1983, 0
Offset: 1
Examples
Some solutions for n=4 k=4 ..1..2..3..4.14...10..2.12..4.14....1..2.12..4.14...10..2..3..4.14 .15..0..8..9.19....6..0..1..9..3...15..0..8..9..3....6..0..1..9.19 .20..5..6..7.24...20..5.22..7..8...20..5..6..7.24...20..5.22..7..8 .16.10.11.12.13...16.17.11.19.13...16.10.11.19.13...16.17.11.12.13 .21.22.23.17.18...21.15.23.24.18...21.22.23.17.18...21.15.23.24.18
Links
- R. H. Hardin, Table of n, a(n) for n = 1..179
Formula
Empirical for column k:
k=1: a(n) = a(n-1) +a(n-5)
k=2: a(n) = a(n-1)
k=3: [order 45]
k=4: a(n) = 3*a(n-1) for n>3
Empirical for row n:
n=1: a(n) = a(n-2)
n=2: [order 20]
n=3: [order 46]
Comments