A257440 - OEIS

%I #8 Dec 21 2018 07:49:48

%S 30,36,39,49,65,90,128,186,269,392,573,836,1223,1791,2621,3839,5625,

%T 8240,12074,17694,25928,37997,55686,81608,119600,175281,256883,376478,

%U 551754,808631,1185104,1736853,2545478,3730577,5467425,8012897,11743469

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

%H R. H. Hardin, <a href="/A257440/b257440.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = a(n-1) + 2*a(n-3) - a(n-4) - a(n-6) for n>12.

%F Empirical g.f.: x*(30 + 6*x + 3*x^2 - 50*x^3 - 26*x^4 - 17*x^5 + 9*x^6 + 13*x^7 + 7*x^8 + 6*x^9 + 2*x^10 + x^11) / ((1 - x)*(1 + x + x^2)*(1 - x - x^3)). - _Colin Barker_, Dec 21 2018

%e Some solutions for n=4:

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

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

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

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

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

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

%Y Column 1 of A257447.

%K nonn

%O 1,1

%A _R. H. Hardin_, Apr 23 2015