A262918 Number of (4+1) X (n+1) 0..1 arrays with each row divisible by 3 and each column divisible by 7, read as a binary number with top and left being the most significant bits.

5, 9, 53, 137, 853, 2953, 17333, 71721, 394325, 1791209, 9435253, 44924617, 230950613, 1126125513, 5713545653, 28200027881, 142082597845, 705663892009, 3542422689653, 17650591452297, 88436516562773, 441384307595273

Offset

1,1

Links

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

Formula

Empirical: a(n) = 7*a(n-1) + 11*a(n-2) - 147*a(n-3) + 99*a(n-4) + 777*a(n-5) - 1019*a(n-6) - 637*a(n-7) + 910*a(n-8).

Empirical g.f.: x*(5 - 26*x - 65*x^2 + 402*x^3 + 139*x^4 - 1510*x^5 + 273*x^6 + 910*x^7) / ((1 - x)*(1 + x)*(1 - 2*x)*(1 - 5*x)*(1 - 7*x^2)*(1 - 13*x^2)). - Colin Barker, Jan 01 2019

Example

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

Crossrefs

Row 4 of A262917.

Sequence in context: A123817 A369155 A124421 * A283918 A284382 A143554

Adjacent sequences: A262915 A262916 A262917 * A262919 A262920 A262921

Keyword

nonn

Author

R. H. Hardin, Oct 04 2015

Status

approved