cp's OEIS Frontend

A252525 Number of (n+2)X(1+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 2 3 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 2 3 6 or 7.

%I A252525 #6 Jun 02 2025 11:20:00
%S A252525 750,595,460,535,546,649,823,1036,1328,1756,2254,2949,3882,5007,6535,
%T A252525 8608,11078,14439,18930,24343,31630,41368,53110,68859,89778,115127,
%U A252525 148930,193720,248118,320379,415794,532023,685810,888376,1135670,1461819
%N A252525 Number of (n+2)X(1+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 2 3 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 2 3 6 or 7.
%C A252525 Column 1 of A252532
%H A252525 R. H. Hardin, <a href="/A252525/b252525.txt">Table of n, a(n) for n = 1..210</a>
%F A252525 Empirical: a(n) = 4*a(n-3) -3*a(n-6) -4*a(n-9) +4*a(n-12) for n>23
%e A252525 Some solutions for n=4
%e A252525 ..0..3..3....2..3..2....3..2..2....3..3..1....0..2..0....3..3..0....2..1..3
%e A252525 ..2..3..2....2..2..3....3..0..0....3..2..2....3..2..1....1..0..1....2..0..0
%e A252525 ..3..3..0....1..3..3....2..2..3....2..3..2....2..0..0....1..1..0....1..0..1
%e A252525 ..3..2..2....2..3..2....3..2..2....3..3..0....0..3..3....2..0..0....1..1..0
%e A252525 ..2..3..2....2..2..3....3..0..3....3..2..2....2..2..2....1..0..1....3..0..0
%e A252525 ..3..3..1....1..3..3....2..2..3....2..3..2....3..0..0....1..1..0....1..0..1
%K A252525 nonn
%O A252525 1,1
%A A252525 _R. H. Hardin_, Dec 18 2014