A297654 T(n,k)=Number of nXk 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 1, 2 or 3 neighboring 1s.
1, 2, 1, 4, 10, 1, 7, 43, 36, 1, 12, 140, 231, 126, 1, 21, 494, 1073, 1421, 454, 1, 37, 1845, 6838, 11024, 9033, 1632, 1, 65, 6757, 45036, 131044, 113252, 55706, 5854, 1, 114, 24479, 268655, 1580681, 2525244, 1105531, 346032, 21010, 1, 200, 89068, 1617465
Offset: 1
Examples
Some solutions for n=4 k=4 ..0..1..1..0. .0..0..0..1. .0..1..1..0. .0..0..1..0. .1..1..1..1 ..0..0..0..0. .0..0..1..1. .0..0..0..1. .1..0..0..1. .0..0..0..1 ..1..1..1..1. .0..0..0..0. .1..1..0..0. .0..1..1..0. .1..1..0..0 ..0..1..0..0. .0..0..1..1. .1..1..0..0. .1..0..0..0. .1..1..1..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..219
Formula
Empirical for column k:
k=1: a(n) = a(n-1)
k=2: a(n) = 3*a(n-1) +a(n-2) +4*a(n-3)
k=3: [order 11]
k=4: [order 24]
k=5: [order 60]
Empirical for row n:
n=1: a(n) = 2*a(n-1) -a(n-2) +a(n-3)
n=2: a(n) = 3*a(n-1) -2*a(n-2) +13*a(n-3) +6*a(n-4) +12*a(n-5) +12*a(n-6)
n=3: [order 17]
n=4: [order 38]
Comments