A252608 - OEIS

%I #4 Dec 19 2014 10:19:18

%S 614,725,1042,1635,3022,5503,9927,19165,36457,66942,130253,250493,

%T 461838,901547,1740381,3212610,6279191,12136529,22411460,43823953,

%U 84734165,156496838,306070623,591832623,1093177438,2138153485,4134310387

%N Number of (n+2)X(1+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 3 5 6 or 8 and every 3X3 column and antidiagonal sum not equal to 0 3 5 6 or 8

%C Column 1 of A252615

%H R. H. Hardin, <a href="/A252608/b252608.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 21*a(n-3) +a(n-4) -166*a(n-6) -19*a(n-7) +635*a(n-9) +128*a(n-10) -1321*a(n-12) -379*a(n-13) +1640*a(n-15) +563*a(n-16) -1416*a(n-18) -514*a(n-19) +944*a(n-21) +388*a(n-22) -336*a(n-24) -168*a(n-25) for n>31

%e Some solutions for n=4

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

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 19 2014