A262466 Number of (n+1) X (2+1) 0..1 arrays with each row divisible by 3 and each column divisible by 5, read as a binary number with top and left being the most significant bits.

1, 3, 9, 17, 37, 107, 321, 865, 2449, 7299, 21897, 64625, 192277, 576299, 1728897, 5174977, 15507361, 46516227, 139548681, 418517201, 1255358341, 3766010603, 11298031809, 33892678177, 101675908657, 305027017347, 915081052041

Offset: 1

Author

R. H. Hardin, Sep 23 2015

Keywords

• nonn

Comments

Column 2 of A262472.

Examples

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

Links

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

Crossrefs

Cf. A262472.

Formula

Empirical: a(n) = 4*a(n-1) - 4*a(n-2) + 4*a(n-3) + 8*a(n-4) - 44*a(n-5) + 44*a(n-6) - 44*a(n-7) + 33*a(n-8).

Empirical g.f.: x*(1 - x + x^2 - 11*x^3 - 15*x^4 + 11*x^5 - 11*x^6 + 33*x^7) / ((1 - x)*(1 - 3*x)*(1 + x^2)*(1 - 11*x^4)). - Colin Barker, Mar 20 2018