A227022 - OEIS

%I #4 Jun 27 2013 20:32:12

%S 12,72,335,1366,4948,16115,47659,129463,326522,771653,1722005,3652726,

%T 7406710,14426468,27103102,49288384,87029344,149600861,250930856,

%U 411535151,661105246,1041922558,1613307461,2457351181,3686223670

%N 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

%C Column 3 of A227025

%H R. H. Hardin, <a href="/A227022/b227022.txt">Table of n, a(n) for n = 1..210</a>

%F 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

%e Some solutions for n=4

%e ..0..0..0....0..1..0....0..0..2....0..1..1....0..0..1....0..1..2....0..0..1

%e ..0..0..0....0..0..0....0..0..2....1..1..1....0..1..1....0..2..2....1..2..1

%e ..0..1..0....1..1..1....0..1..1....0..0..1....1..0..0....1..0..0....2..2..2

%e ..1..0..0....2..2..0....1..1..1....1..1..0....0..0..0....1..0..0....2..2..2

%K nonn

%O 1,1

%A _R. H. Hardin_ Jun 27 2013