A208635 - OEIS

%I #8 Jul 05 2018 08:44:18

%S 32,95,309,1042,3577,12404,43284,151656,532795,1875161,6607478,

%T 23301225,82215220,290187784,1024490960,3617470935,12774594765,

%U 45114821146,159335044937,562751474084,1987608261228,7020221345560,24795605196403

%N Number of n X 6 0..1 arrays with new values 0..1 introduced in row major order and no element equal to more than one of its immediate leftward or upward or right-upward antidiagonal neighbors.

%C Column 6 of A208637.

%H R. H. Hardin, <a href="/A208635/b208635.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 7*a(n-1) - 15*a(n-2) + 10*a(n-3) - a(n-4).

%F Empirical g.f.: x*(32 - 129*x + 124*x^2 - 16*x^3) / ((1 - x)*(1 - 6*x + 9*x^2 - x^3)). - _Colin Barker_, Jul 05 2018

%e Some solutions for n=4:

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

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

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

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

%Y Cf. A208637.

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 29 2012