A302278 T(n,k) = number of n X k 0..1 arrays with every element equal to 1, 2 or 4 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, 79, 61, 0, 8, 45, 74, 89, 269, 162, 0, 13, 98, 162, 283, 353, 942, 421, 0, 21, 193, 363, 649, 1219, 941, 3401, 1103, 0, 34, 379, 782, 1621, 3621, 3854, 3316, 12283, 2890, 0, 55, 778, 1766, 4209, 14125, 15862, 14639
Offset: 1
Examples
Some solutions for n=5, k=4: 0 0 1 1 0 1 1 1 0 0 0 0 0 0 0 0 0 0 1 0 1 1 0 0 0 0 1 0 1 1 1 1 0 1 0 1 1 1 0 0 1 0 1 0 0 0 0 0 0 1 0 1 1 0 1 0 0 0 0 1 1 0 1 0 0 1 1 1 1 0 1 0 1 1 1 1 0 1 1 1 0 1 0 1 1 0 0 0 0 1 0 1 0 0 0 0 1 1 0 0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..220
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 18]
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 64] for n > 66
Comments