A264490 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 2,-1 1,0 2,1 0,-1 -2,-2 or -1,0.
1, 1, 3, 1, 1, 4, 1, 10, 12, 12, 1, 8, 36, 16, 25, 1, 35, 108, 212, 214, 52, 1, 42, 324, 788, 2144, 324, 121, 1, 130, 972, 4772, 21466, 9714, 2960, 261, 1, 194, 2916, 23076, 217049, 142352, 92052, 6442, 576, 1, 501, 8748, 122628, 2186741, 2517024, 2870927, 581575
Offset: 1
Examples
Some solutions for n=4 k=4 ..5..6..7..8..9....5..6..7..4..9....5..6..7..8..9....5..2..7..8..9 ..0.11..2.13.14...10.11.12.13.14...10.11..2.13..4....0.11.12..3..4 .22.16..1..4..3...22..0..1..2..3...22..0..1.14..3...22.16..1.18.19 .20.21.18.23.24...20.21..8.23.24...20.21.18.23.24...20.21..6.23.14 .15.10.17.12.19...15.16.17.18.19...15.16.17.12.19...15.10.17.24.13
Links
- R. H. Hardin, Table of n, a(n) for n = 1..98
Crossrefs
Row 3 is A003946.
Formula
Empirical for column k:
k=1: a(n) = 2*a(n-1) +a(n-3) -2*a(n-4) +4*a(n-5) +a(n-6) -a(n-9)
k=2: [order 36]
Empirical for row n:
n=1: a(n) = a(n-1)
n=2: a(n) = 3*a(n-2) +2*a(n-3) +a(n-4) -a(n-5)
n=3: a(n) = 3*a(n-1)
n=4: a(n) = a(n-1) +16*a(n-2) +24*a(n-3) +16*a(n-4) +32*a(n-5) +32*a(n-6)
n=5: [order 39]
n=6: [order 10] for n>11
Comments