A252722 Number of (3+2) X (n+2) 0..3 arrays with every consecutive three elements in every row and diagonal having exactly two distinct values, and in every column and antidiagonal not having exactly two distinct values, and new values 0 upwards introduced in row major order.

54, 56, 62, 70, 86, 110, 114, 158, 194, 214, 290, 374, 402, 566, 722, 790, 1106, 1430, 1554, 2198, 2834, 3094, 4370, 5654, 6162, 8726, 11282, 12310, 17426, 22550, 24594, 34838, 45074, 49174, 69650, 90134, 98322, 139286, 180242, 196630, 278546, 360470

Offset

1,1

Links

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

Formula

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

Empirical g.f.: 2*x*(27 + 28*x + 4*x^2 - 47*x^3 - 44*x^4 + 12*x^5) / ((1 - x)*(1 + x)*(1 - 2*x^3)). - Colin Barker, Dec 05 2018

Example

Some solutions for n=4:
..0..0..1..0..0..1....0..1..0..0..1..0....0..0..1..0..0..1....0..1..1..2..1..1
..0..2..2..0..2..2....1..1..2..1..1..2....2..1..1..3..1..1....1..0..1..1..2..1
..0..1..0..0..1..0....2..1..1..2..1..1....1..2..1..1..3..1....3..3..1..3..3..1
..0..0..1..0..0..1....3..1..3..3..1..3....0..0..1..0..0..1....0..1..1..0..1..1
..0..3..3..0..3..3....1..1..2..1..1..2....3..1..1..2..1..1....1..2..1..1..0..1

Crossrefs

Row 3 of A252719.

Sequence in context: A247900 A116386 A107936 * A326181 A300447 A344809

Adjacent sequences: A252719 A252720 A252721 * A252723 A252724 A252725

Keyword

nonn

Author

R. H. Hardin, Dec 20 2014

Status

approved