A303084 T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 2, 3, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1, 1, 2, 1, 2, 4, 1, 12, 2, 8, 1, 20, 32, 3, 16, 1, 72, 29, 112, 6, 32, 1, 168, 258, 90, 416, 10, 64, 1, 496, 432, 1455, 304, 1512, 21, 128, 1, 1296, 2525, 3667, 11767, 1054, 5472, 42, 256, 1, 3616, 6313, 33152, 34430, 84474, 4182, 19904, 86, 512, 1, 9760, 30188, 157838
Offset: 1
Examples
Some solutions for n=5 k=4 ..0..0..0..1. .0..1..1..1. .0..0..1..1. .0..1..1..1. .0..0..0..1 ..0..0..0..1. .1..1..1..1. .0..0..1..1. .1..1..1..1. .1..0..0..1 ..0..1..0..1. .0..0..0..0. .1..0..0..0. .0..1..0..1. .1..0..0..1 ..0..0..0..0. .0..0..0..0. .1..0..0..1. .1..1..1..1. .0..0..0..1 ..0..0..0..1. .0..0..0..0. .0..0..0..1. .0..1..1..1. .1..0..0..1
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 11]
k=4: [order 56] for n>57
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 17] for n>18
n=4: [order 67] for n>68
Comments