A302427 T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 1, 3 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1, 2, 2, 3, 3, 4, 5, 9, 6, 8, 8, 17, 11, 10, 16, 13, 25, 21, 21, 21, 32, 21, 65, 38, 42, 51, 42, 64, 34, 185, 88, 83, 148, 93, 86, 128, 55, 385, 188, 235, 372, 362, 207, 179, 256, 89, 649, 377, 532, 1359, 992, 879, 517, 370, 512, 144, 1489, 735, 1250, 4223, 4231, 2503, 2447
Offset: 1
Examples
Some solutions for n=5 k=4 ..0..0..1..1. .0..1..0..1. .0..1..0..1. .0..1..0..1. .0..1..0..1 ..0..1..0..1. .0..1..0..1. .1..1..0..1. .0..1..0..0. .1..1..0..1 ..0..1..0..1. .0..1..1..0. .0..1..0..1. .0..1..0..1. .0..1..0..1 ..1..0..0..1. .1..0..1..0. .0..1..0..1. .1..1..0..1. .0..1..0..0 ..1..0..1..0. .1..0..1..0. .0..1..1..0. .0..1..0..1. .0..1..0..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..286
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: a(n) = a(n-1) +10*a(n-3) -8*a(n-4) for n>9
k=4: [order 42] for n>43
k=5: [order 21] for n>24
Empirical for row n:
n=1: a(n) = a(n-1) +a(n-2)
n=2: a(n) = a(n-1) +16*a(n-4) -8*a(n-5) for n>6
n=3: [order 18] for n>19
n=4: [order 68] for n>69
Comments