A302635 T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 1, 3 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1, 2, 2, 3, 3, 4, 5, 9, 6, 8, 8, 17, 8, 10, 16, 13, 25, 14, 19, 21, 32, 21, 65, 25, 33, 42, 42, 64, 34, 185, 47, 65, 101, 82, 86, 128, 55, 385, 83, 149, 257, 248, 189, 179, 256, 89, 649, 150, 304, 691, 719, 657, 469, 370, 512, 144, 1489, 269, 643, 1734, 2262, 2303, 1841, 1029
Offset: 1
Examples
Some solutions for n=5 k=4 ..0..0..1..0. .0..1..0..1. .0..1..0..1. .0..0..1..1. .0..1..0..1 ..1..1..1..0. .0..1..0..1. .0..1..0..0. .0..1..0..1. .0..0..0..1 ..0..0..0..0. .0..1..1..1. .0..1..0..1. .0..1..0..1. .0..1..0..1 ..0..1..1..1. .0..1..0..1. .0..0..1..0. .0..1..0..1. .0..1..0..1 ..0..1..0..0. .0..1..0..1. .1..1..1..0. .0..0..1..1. .0..1..1..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..391
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) +9*a(n-3) -4*a(n-4) +2*a(n-5) -10*a(n-6) +4*a(n-7) +4*a(n-9) for n>13
k=4: [order 21] for n>25
k=5: [order 29] for n>32
k=6: [order 54] for n>65
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: a(n) = a(n-1) +a(n-2) +2*a(n-4) -a(n-5) for n>7
n=4: [order 22] for n>23
n=5: [order 63] for n>64
n=6: [order 81] for n>86
Comments