A251646 - OEIS

%I #4 Dec 06 2014 10:43:27

%S 448,908,1928,4008,10248,22904,49956,129296,300656,689192,1792064,

%T 4317696,10331264,26936064,66797136,165179552,431375936,1092206912,

%U 2762577872,7222018464,18536302352,47560605216,124411054752,322001817152

%N Number of (n+2)X(2+2) 0..3 arrays with no row, column, diagonal or antidiagonal in any 3X3 subblock summing to 0 2 4 5 7 or 9

%C Column 2 of A251652

%H R. H. Hardin, <a href="/A251646/b251646.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 4*a(n-1) -2*a(n-2) +4*a(n-3) -36*a(n-4) +22*a(n-5) +59*a(n-6) -40*a(n-7) -20*a(n-8) +10*a(n-9) for n>15

%e Some solutions for n=4

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

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 06 2014