A303314 T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 1, 4, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1, 2, 2, 3, 3, 4, 5, 3, 4, 8, 8, 5, 12, 6, 16, 13, 7, 17, 11, 9, 32, 21, 13, 24, 36, 19, 14, 64, 34, 23, 67, 50, 74, 34, 22, 128, 55, 37, 158, 128, 139, 165, 53, 35, 256, 89, 63, 298, 439, 410, 349, 361, 83, 56, 512, 144, 109, 595, 1085, 1799, 1221, 853, 783, 136, 90, 1024, 233
Offset: 1
Examples
Some solutions for n=5 k=4 ..0..1..0..0. .0..1..1..1. .0..0..0..1. .0..1..0..0. .0..1..0..1 ..0..1..1..1. .0..1..0..1. .0..1..0..1. .0..1..1..1. .0..1..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. .0..1..0..1. .0..0..0..1. .0..1..0..1. .0..1..0..1 ..0..0..0..1. .0..0..0..1. .1..1..0..1. .0..1..0..1. .0..1..0..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..511
Crossrefs
Formula
Empirical for column k:
k=1: a(n) = 2*a(n-1)
k=2: a(n) = 2*a(n-1) -a(n-3)
k=3: a(n) = a(n-1) +a(n-3) +a(n-4) for n>7
k=4: a(n) = a(n-1) +a(n-2) +3*a(n-3) +2*a(n-4) -a(n-5) -2*a(n-6) -a(n-7) for n>10
k=5: a(n) = a(n-1) +9*a(n-3) +2*a(n-4) +4*a(n-5) -10*a(n-6) -6*a(n-7) +4*a(n-9) for n>12
k=6: [order 8] for n>11
k=7: [order 20] for n>23
Empirical for row n:
n=1: a(n) = a(n-1) +a(n-2)
n=2: a(n) = a(n-1) +2*a(n-3) for n>5
n=3: a(n) = a(n-1) +3*a(n-3) +4*a(n-4) for n>7
n=4: a(n) = a(n-1) +a(n-2) +5*a(n-3) +9*a(n-4) -3*a(n-5) -7*a(n-6) -2*a(n-7) for n>11
n=5: [order 12] for n>16
n=6: [order 23] for n>28
n=7: [order 46] for n>51
Comments