A203980 Number of (n+1) X 5 0..2 arrays with no 2 X 2 subblock having equal diagonal elements or equal antidiagonal elements, and new values 0..2 introduced in row major order.

384, 5184, 69984, 956448, 13071456, 178855776, 2447270496, 33489653472, 458288894304, 6271519652064, 85823503984224, 1174465206026208, 16072153386090336, 219941927082883296, 3009830115907061856

Offset

1,1

Comments

Column 4 of A203984.

Links

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

Formula

Empirical: a(n) = 15*a(n-1) - 270*a(n-3) + 324*a(n-4).

Empirical g.f.: 96*x*(4 - 6*x - 81*x^2 + 108*x^3) / ((1 - 15*x + 18*x^2)*(1 - 18*x^2)). - Colin Barker, Jun 06 2018

Example

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

Crossrefs

Cf. A203984.

Sequence in context: A252899 A183686 A134241 * A061403 A281656 A128967

Adjacent sequences: A203977 A203978 A203979 * A203981 A203982 A203983

Keyword

nonn

Author

R. H. Hardin, Jan 09 2012

Status

approved