A262314 Number of (n+2)X(2+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.

3, 5, 9, 27, 61, 145, 435, 1253, 3593, 10779, 32445, 96881, 290643, 875365, 2627721, 7883163, 23685949, 71096657, 213289971, 640160485, 1920877321, 5762631963, 17289819325, 51872540977, 155617622931, 466863471461, 1400610395529

Offset

1,1

Comments

Column 2 of A262319.

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 4*a(n-1) -4*a(n-2) +20*a(n-3) -68*a(n-4) +68*a(n-5) -162*a(n-6) +444*a(n-7) -444*a(n-8) +644*a(n-9) -1244*a(n-10) +1244*a(n-11) -1277*a(n-12) +1376*a(n-13) -1376*a(n-14) +1032*a(n-15)

Example

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

Crossrefs

Cf. A262319.

Sequence in context: A004044 A192152 A217098 * A338604 A209286 A082711

Adjacent sequences: A262311 A262312 A262313 * A262315 A262316 A262317

Keyword

nonn

Author

R. H. Hardin, Sep 17 2015

Status

approved