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A252568 Number of (n+2)X(2+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 1 2 5 6 or 7 and every 3X3 column and antidiagonal sum not equal to 1 2 5 6 or 7.

%I A252568 #6 Jun 02 2025 11:23:10
%S A252568 843,868,1558,3286,7610,17261,39419,94224,218717,504824,1216914,
%T A252568 2842764,6585725,15930113,37308440,86581201,209741403,491769283,
%U A252568 1142254876,2768731230,6494985545,15093638282,36592496037,85859457999,199589766685
%N A252568 Number of (n+2)X(2+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 1 2 5 6 or 7 and every 3X3 column and antidiagonal sum not equal to 1 2 5 6 or 7.
%C A252568 Column 2 of A252574
%H A252568 R. H. Hardin, <a href="/A252568/b252568.txt">Table of n, a(n) for n = 1..210</a>
%F A252568 Empirical: a(n) = 41*a(n-3) -642*a(n-6) +4961*a(n-9) -21249*a(n-12) +55203*a(n-15) -94450*a(n-18) +115159*a(n-21) -104947*a(n-24) +71287*a(n-27) -34926*a(n-30) +11911*a(n-33) -2699*a(n-36) +381*a(n-39) -30*a(n-42) +a(n-45) for n>50
%e A252568 Some solutions for n=4
%e A252568 ..2..2..3..1....2..2..3..2....2..0..0..1....3..2..2..3....0..0..1..0
%e A252568 ..1..0..0..2....2..0..0..1....2..3..2..2....0..2..0..0....2..0..0..1
%e A252568 ..0..2..0..0....0..1..0..0....0..0..2..0....0..0..1..0....2..3..2..2
%e A252568 ..2..2..3..2....2..2..3..2....2..0..0..2....3..2..2..3....0..0..1..0
%e A252568 ..1..0..0..1....1..0..0..2....1..3..2..1....1..1..0..0....1..0..0..2
%e A252568 ..0..1..0..0....0..2..0..0....0..0..1..0....0..0..2..0....2..3..2..2
%K A252568 nonn
%O A252568 1,1
%A A252568 _R. H. Hardin_, Dec 18 2014