A302728 T(n,k)=Number of nXk 0..1 arrays with every element equal to 1, 2, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
0, 1, 0, 1, 3, 0, 2, 7, 10, 0, 3, 10, 22, 23, 0, 5, 27, 29, 83, 61, 0, 8, 45, 74, 89, 301, 162, 0, 13, 98, 162, 287, 353, 1079, 421, 0, 21, 193, 363, 689, 1307, 941, 4064, 1103, 0, 34, 379, 782, 1723, 4505, 4491, 3316, 15183, 2890, 0, 55, 778, 1766, 4491, 16265, 20842, 17828
Offset: 1
Examples
Some solutions for n=5 k=4 ..0..0..0..0. .0..1..1..1. .0..0..1..1. .0..1..0..1. .0..1..1..0 ..1..0..1..0. .1..0..0..0. .0..0..1..1. .1..0..1..0. .0..0..0..0 ..0..1..0..1. .1..1..1..1. .0..1..0..1. .0..1..0..1. .0..1..1..0 ..1..0..1..0. .0..1..1..1. .0..1..1..0. .1..0..1..0. .0..0..0..0 ..1..1..1..1. .1..0..0..0. .1..0..0..1. .0..0..0..0. .0..1..1..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..220
Crossrefs
Formula
Empirical for column k:
k=1: a(n) = a(n-1)
k=2: a(n) = 2*a(n-1) +a(n-2) +2*a(n-3) -a(n-4)
k=3: [order 16]
k=4: [order 72] for n>73
Empirical for row n:
n=1: a(n) = a(n-1) +a(n-2)
n=2: a(n) = a(n-1) +3*a(n-2) -4*a(n-4) for n>5
n=3: [order 16] for n>18
n=4: [order 68] for n>69
Comments