A209594 Number of 3 X 3 0..n arrays with every element equal to a diagonal or antidiagonal reflection.

192, 3645, 28672, 140625, 513216, 1529437, 3932160, 9034497, 19000000, 37202781, 68677632, 120670225, 203297472, 330328125, 520093696, 796539777, 1190427840, 1740697597, 2496000000, 3516410961, 4875335872, 6661615005, 8981839872

Offset: 1

Author

R. H. Hardin, Mar 10 2012

Keywords

• nonn

Comments

Row 3 of A209593.

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..50

Crossrefs

Cf. A209593.

Programs

PARI

a(n) = (2*n+1)*(n+1)^6; \\ Altug Alkan, Jul 11 2018

Formula

a(n) = (n+1) ^ 6 * (2*n+1).

From Colin Barker, Jul 11 2018: (Start)

G.f.: x*(192 + 2109*x + 4888*x^2 + 2557*x^3 + 352*x^4 - 25*x^5 + 8*x^6 - x^7) / (1 - x)^8.

a(n) = 8*a(n-1) - 28*a(n-2) + 56*a(n-3) - 70*a(n-4) + 56*a(n-5) - 28*a(n-6) + 8*a(n-7) - a(n-8) for n>7.

(End)