A252386 - OEIS

%I #4 Dec 17 2014 08:56:57

%S 540,555,647,771,1067,1496,1928,2662,3856,5074,7024,10213,13505,18776,

%T 27325,36221,50467,73399,97476,135968,197447,262661,366593,531297,

%U 707931,988319,1429275,1907450,2663225,3843093,5136589,7172051,10327393

%N Number of (2+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 3 5 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 3 5 6 or 7

%C Row 2 of A252384

%H R. H. Hardin, <a href="/A252386/b252386.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 9*a(n-3) -32*a(n-6) +58*a(n-9) -58*a(n-12) +32*a(n-15) -9*a(n-18) +a(n-21) for n>30

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 17 2014