A303469 T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 1, 2, 3, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1, 2, 2, 4, 8, 4, 8, 29, 32, 8, 16, 105, 170, 128, 16, 32, 384, 948, 1033, 512, 32, 64, 1405, 5237, 9110, 6369, 2048, 64, 128, 5135, 29009, 79377, 89371, 39098, 8192, 128, 256, 18766, 160590, 692636, 1243692, 872026, 240109, 32768, 256, 512, 68589, 888993
Offset: 1
Examples
Some solutions for n=5 k=4 ..0..1..0..0. .0..0..1..0. .0..0..1..0. .0..0..0..1. .0..0..1..0 ..1..1..1..1. .1..0..1..1. .1..1..1..0. .1..0..1..0. .1..0..0..0 ..0..0..0..0. .0..1..0..0. .1..1..1..1. .0..0..1..1. .0..1..1..0 ..0..1..1..0. .0..1..0..1. .0..0..1..0. .0..0..0..0. .0..1..1..0 ..1..0..0..0. .0..0..1..0. .0..0..1..0. .1..1..1..1. .1..1..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..180
Crossrefs
Formula
Empirical for column k:
k=1: a(n) = 2*a(n-1)
k=2: a(n) = 4*a(n-1)
k=3: a(n) = 7*a(n-1) -5*a(n-2) +20*a(n-3) -144*a(n-4) +72*a(n-5) for n>6
k=4: [order 20] for n>21
k=5: [order 93] for n>94
Empirical for row n:
n=1: a(n) = 2*a(n-1)
n=2: a(n) = 3*a(n-1) +a(n-2) +4*a(n-3) +4*a(n-4)
n=3: [order 14] for n>15
n=4: [order 49] for n>50
Comments