A262319 T(n,k)=Number of (n+2)X(k+2) 0..1 arrays with each row and column divisible by 7, read as a binary number with top and left being the most significant bits.

2, 3, 3, 5, 5, 5, 10, 9, 9, 10, 19, 27, 17, 27, 19, 37, 61, 133, 133, 61, 37, 74, 145, 361, 1618, 361, 145, 74, 147, 435, 1009, 6043, 6043, 1009, 435, 147, 293, 1253, 8357, 42661, 37873, 42661, 8357, 1253, 293, 586, 3593, 33993, 683218, 413893, 413893, 683218

Offset: 1

Author

R. H. Hardin, Sep 17 2015

Keywords

• nonn
• tabl

Comments

Table starts

...2.....3......5.......10........19........37........74........147........293

...3.....5......9.......27........61.......145.......435.......1253.......3593

...5.....9.....17......133.......361......1009......8357......33993.....127121

..10....27....133.....1618......6043.....42661....683218....4276587...39384421

..19....61....361.....6043.....37873....413893...8003035..103003837.1659181705

..37...145...1009....42661....413893...7914829.281951533.7901300449

..74...435...8357...683218...8003035.281951533

.147..1253..33993..4276587.103003837

.293..3593.127121.39384421

.586.10779.795013

Examples

			Some solutions for n=4 k=4
..0..1..0..1..0..1....1..0..0..0..1..1....0..1..0..1..0..1....0..0..0..1..1..1
..1..0..1..0..1..0....1..0..0..0..1..1....1..1..1..1..1..1....0..0..0..1..1..1
..1..1..1..1..1..1....0..0..0..1..1..1....1..1..1..1..1..1....0..0..0..0..0..0
..1..0..1..0..1..0....0..0..1..1..1..0....1..1..1..1..1..1....1..1..1..0..0..0
..0..1..0..1..0..1....0..0..1..1..1..0....0..1..0..1..0..1....1..1..1..0..0..0
..0..0..0..0..0..0....1..0..1..0..1..0....0..1..0..1..0..1....1..1..1..1..1..1
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..84

Crossrefs

Column 1 is A046630.

Formula

Empirical for column k:

k=1: a(n) = 2*a(n-1) +a(n-3) -2*a(n-4)

k=2: [order 15]

k=3: [order 43]

k=4: [order 29]