A300776 T(n,k)=Number of nXk 0..1 arrays with every element equal to 2, 3, 4 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.
0, 0, 0, 0, 1, 0, 0, 2, 2, 0, 0, 4, 3, 4, 0, 0, 9, 11, 11, 9, 0, 0, 19, 32, 36, 32, 19, 0, 0, 41, 102, 179, 179, 102, 41, 0, 0, 88, 330, 735, 1536, 735, 330, 88, 0, 0, 189, 1059, 3482, 10374, 10374, 3482, 1059, 189, 0, 0, 406, 3418, 15986, 78932, 116954, 78932, 15986, 3418
Offset: 1
Examples
Some solutions for n=5 k=4 ..0..0..1..1. .0..0..1..1. .0..0..1..1. .0..0..0..0. .0..0..1..1 ..0..0..1..1. .0..1..1..1. .0..1..1..1. .0..1..1..0. .0..1..1..1 ..0..0..1..0. .1..0..0..1. .0..1..1..1. .0..1..0..1. .0..0..0..0 ..1..1..0..0. .1..0..0..1. .0..0..0..1. .0..0..1..1. .0..0..0..0 ..1..0..0..0. .1..1..1..1. .0..0..1..1. .0..1..1..1. .0..0..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..219
Crossrefs
Column 2 is A078039(n-2).
Formula
Empirical for column k:
k=1: a(n) = a(n-1)
k=2: a(n) = a(n-1) +2*a(n-2) +a(n-3)
k=3: [order 15]
k=4: [order 56] for n>57
Comments