A229571 - OEIS

A229571

Number of defective 4-colorings of an n X n 0..3 array connected horizontally, vertically, diagonally and antidiagonally with exactly one mistake, and colors introduced in row-major 0..3 order.

%I #11 Apr 27 2021 21:14:16

%S 0,6,76,312,924,2440,6108,14840,35356,83016,192636,442552,1007868,

%T 2277704,5112220,11403768,25297500,55837384,122684220,268436408,

%U 585106492

%N Number of defective 4-colorings of an n X n 0..3 array connected horizontally, vertically, diagonally and antidiagonally with exactly one mistake, and colors introduced in row-major 0..3 order.

%C Diagonal of A229578.

%F Empirical (for n>=9): a(n) = 9*a(n-1) - 33*a(n-2) + 63*a(n-3) - 66*a(n-4) + 36*a(n-5) - 8*a(n-6). - _Vaclav Kotesovec_, Feb 14 2014

%e Some solutions for n=3:

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

%e 3 2 3 2 3 2 1 2 3 2 3 2 2 2 3 2 3 3 2 1 0

%e 1 0 1 0 1 2 3 0 1 0 1 0 1 0 1 1 0 1 0 3 2

%Y Cf. A229578.

%K nonn

%O 1,2

%A _R. H. Hardin_, Sep 26 2013