A258958 - OEIS

%I #9 Dec 23 2018 08:56:12

%S 66,344,192,312,384,694,720,1210,1440,2674,2880,4840,5760,10696,11520,

%T 19360,23040,42784,46080,77440,92160,171136,184320,309760,368640,

%U 684544,737280,1239040,1474560,2738176,2949120,4956160,5898240,10952704

%N Number of (n+2) X (n+2) 0..1 arrays with no 3 X 3 subblock diagonal sum 0 and no antidiagonal sum 3 and no row sum 0 or 3 and no column sum 0 or 3.

%H R. H. Hardin, <a href="/A258958/b258958.txt">Table of n, a(n) for n = 1..53</a>

%F Empirical: a(n) = 4*a(n-4) for n>10.

%F Empirical g.f.: 2*x*(33 + 172*x + 96*x^2 + 156*x^3 + 60*x^4 - 341*x^5 - 24*x^6 - 19*x^7 - 48*x^8 - 51*x^9) / ((1 - 2*x^2)*(1 + 2*x^2)). - _Colin Barker_, Dec 23 2018

%e Some solutions for n=4:

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

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

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

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

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

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

%Y Diagonal of A258966.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jun 15 2015