A302889 T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 2, 3, 4 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1, 1, 2, 1, 2, 4, 1, 12, 2, 8, 1, 20, 37, 3, 16, 1, 72, 53, 141, 6, 32, 1, 168, 197, 238, 569, 10, 64, 1, 496, 818, 2278, 1102, 2262, 21, 128, 1, 1296, 2548, 12782, 20937, 5570, 8968, 42, 256, 1, 3616, 10926, 98458, 200186, 206332, 28594, 35667, 86, 512, 1, 9760, 42671
Offset: 1
Examples
Some solutions for n=5 k=4 ..0..1..1..0. .0..1..1..1. .0..1..1..0. .0..0..0..0. .0..1..1..0 ..1..1..1..0. .1..1..1..0. .0..1..1..0. .1..0..0..1. .0..1..1..1 ..0..1..1..0. .0..1..1..0. .0..1..1..1. .1..0..0..1. .0..1..1..1 ..0..1..1..0. .0..1..1..1. .1..1..1..0. .0..0..0..0. .1..1..1..0 ..0..1..1..1. .0..1..1..0. .0..1..1..1. .0..0..0..1. .1..1..1..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..180
Formula
Empirical for column k:
k=1: a(n) = 2*a(n-1)
k=2: a(n) = 2*a(n-1) +a(n-2) -a(n-3) -2*a(n-4) +a(n-5)
k=3: [order 10]
k=4: [order 35] for n>37
Empirical for row n:
n=1: a(n) = a(n-1)
n=2: a(n) = 2*a(n-1) +4*a(n-2) -4*a(n-3) -4*a(n-4)
n=3: [order 16] for n>17
n=4: [order 51] for n>54
Comments