A251872 - OEIS

%I #4 Dec 10 2014 09:17:04

%S 5756,15116,9936,13152,31520,46464,62720,164480,252736,389376,910400,

%T 1559552,2443264,5882368,10571776,17743872,40570880,77176832,

%U 131203072,302153728,586940416,1020788736,2313420800,4577165312,7994343424

%N Number of (n+2)X(4+2) 0..3 arrays with every 3X3 subblock row and column sum not 2 4 5 or 7 and every diagonal and antidiagonal sum 2 4 5 or 7

%C Column 4 of A251876

%H R. H. Hardin, <a href="/A251872/b251872.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 8*a(n-3) +16*a(n-6) -128*a(n-9) for n>17

%e Some solutions for n=4

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

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 10 2014