A227022 Number of nX3 (0,1,2) arrays of permanents of 2X2 subblocks of some (n+1)X4 binary array with rows and columns of the latter in lexicographically nondecreasing order.

12, 72, 335, 1366, 4948, 16115, 47659, 129463, 326522, 771653, 1722005, 3652726, 7406710, 14426468, 27103102, 49288384, 87029344, 149600861, 250930856, 411535151, 661105246, 1041922558, 1613307461, 2457351181, 3686223670

Offset: 1

Author

R. H. Hardin Jun 27 2013

Keywords

• nonn

Comments

Column 3 of A227025

Examples

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

Links

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

Formula

Empirical: a(n) = (1/2217600)*n^11 + (1/48384)*n^10 + (19/241920)*n^9 + (199/2800)*n^7 - (4291/11520)*n^6 - (3567/1792)*n^5 + (1336261/24192)*n^4 - (95295341/302400)*n^3 + (851237/1440)*n^2 + (8658337/9240)*n - 3550 for n>6