A252546 - OEIS

%I #4 Dec 18 2014 09:12:47

%S 850,3880,15480,43848,213120,881848,2568432,12681664,53297808,

%T 157483872,782763648,3314813344,9868152000,49199192320,209132201280,

%U 624968085888,3120427983360,13288964395648,39789382386432,198807593780224

%N Number of (2+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 1 3 4 6 or 7 and every 3X3 column and antidiagonal sum not equal to 1 3 4 6 or 7

%C Row 2 of A252544

%H R. H. Hardin, <a href="/A252546/b252546.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 118*a(n-3) -4264*a(n-6) +55168*a(n-9) -225280*a(n-12) +262144*a(n-15) for n>16

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 18 2014