A264569 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 1,0 1,1 0,-1 or -1,1.
1, 1, 1, 1, 2, 1, 2, 4, 4, 2, 2, 8, 10, 8, 2, 4, 24, 44, 31, 16, 3, 4, 64, 143, 192, 79, 32, 4, 7, 160, 633, 1130, 888, 224, 64, 5, 9, 384, 2172, 8356, 7808, 4104, 646, 128, 7, 13, 960, 8409, 47571, 96429, 57265, 18540, 1784, 256, 9, 18, 2432, 32046, 305844, 868613
Offset: 1
Examples
Some solutions for n=4 k=4 ..1..2..3..4..8....1..5..6..4..8....1..5..3..4..8....1..2..3..4..8 ..0..7.11..9.13....0..7..2..9..3....0..7..2..9.13....0.10.11.12.13 ..5..6.16.17.18...11.15.16.17.18...11..6.16.17.18....5..6..7.14..9 .10.20.21.12.14...10.20.12.13.14...10.20.21.12.14...16.20.21.19.23 .15.22.23.24.19...21.22.23.24.19...15.22.23.24.19...15.22.17.24.18
Links
- R. H. Hardin, Table of n, a(n) for n = 1..179
Formula
Empirical for column k:
k=1: a(n) = a(n-2) +a(n-3)
k=2: a(n) = 2*a(n-1)
k=3: [order 15]
k=4: a(n) = 18*a(n-2) +36*a(n-3) -45*a(n-4) -216*a(n-5) -243*a(n-6) for n>7
k=5: [order 84]
k=6: [order 36] for n>40
Empirical for row n:
n=1: a(n) = a(n-2) +a(n-3) +a(n-4) -a(n-6)
n=2: a(n) = 2*a(n-1) +8*a(n-4)
n=3: [order 70]
n=4: [order 56]
Comments