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

1,2

Comments

Column 2 of A262472.

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) + 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

Example

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

Crossrefs

Cf. A262472.

Sequence in context: A116688 A293423 A011755 * A128301 A348382 A176148

Adjacent sequences: A262463 A262464 A262465 * A262467 A262468 A262469

Keyword

nonn

Author

R. H. Hardin, Sep 23 2015

Status

approved