A232048 Number of 2 X n 0..1 arrays with no element less than a strict majority of its horizontal and antidiagonal neighbors.

4, 7, 15, 34, 79, 184, 426, 984, 2274, 5258, 12159, 28117, 65018, 150347, 347661, 803931, 1859013, 4298789, 9940535, 22986529, 53154136, 122913828, 284226412, 657246261, 1519818815, 3514434954, 8126793100, 18792428087, 43455684079

Offset

1,1

Links

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

Formula

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

Empirical g.f.: x*(4 - 9*x + 11*x^2 - 12*x^3 + 8*x^4 - 3*x^5 - x^6 + x^7) / ((1 - x + x^2)*(1 - 3*x + 2*x^2 - 2*x^3 + 2*x^4 + x^5)). - Colin Barker, Oct 02 2018

Example

Some solutions for n=7:
..1..1..1..1..0..0..0....1..1..1..0..0..0..1....0..0..0..0..0..1..0
..0..0..0..0..0..1..1....0..0..0..0..0..0..0....0..0..0..0..0..0..0

Crossrefs

Row 2 of A232047.

Sequence in context: A119749 A201498 A145970 * A145795 A173657 A213358

Adjacent sequences: A232045 A232046 A232047 * A232049 A232050 A232051

Keyword

nonn

Author

R. H. Hardin, Nov 17 2013

Status

approved