A241108 T(n,k)=Number of nXk 0..2 arrays with no element equal to one or three horizontal or vertical neighbors, with new values 0..2 introduced in row major order.
1, 1, 1, 2, 4, 2, 4, 11, 11, 4, 8, 36, 58, 36, 8, 16, 116, 294, 294, 116, 16, 32, 376, 1522, 2436, 1522, 376, 32, 64, 1216, 7846, 19814, 19814, 7846, 1216, 64, 128, 3936, 40418, 162776, 259388, 162776, 40418, 3936, 128, 256, 12736, 208374, 1333934, 3374086
Offset: 1
Examples
Some solutions for n=4 k=4 ..0..1..1..2....0..1..1..2....0..1..2..0....0..1..0..2....0..1..2..0 ..2..1..1..0....2..1..1..1....1..2..1..2....1..0..2..1....1..0..0..2 ..1..0..2..1....0..2..1..1....2..1..2..0....2..1..1..0....2..0..0..0 ..0..2..0..2....2..0..2..0....1..2..0..2....0..1..1..2....1..2..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..144
Formula
Empirical for column k:
k=1: a(n) = 2*a(n-1) for n>2
k=2: a(n) = 2*a(n-1) +4*a(n-2) for n>4
k=3: a(n) = 3*a(n-1) +8*a(n-2) +16*a(n-3)
k=4: [order 10]
k=5: [order 26]
k=6: [order 76]
Comments