|
%I #9 Jul 07 2018 06:16:56
%S 22,484,990,11242,33088,272206,992574,6800596,28280758,173714530,
%T 783832896,4504621990,21385325830,117970266436,578059231662,
%U 3109202601274,15538154773504,82277236170910,416242718387694
%N Number of 6 X n 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 1 1 and 1 1 0 vertically.
%C Row 6 of A208840.
%H R. H. Hardin, <a href="/A208843/b208843.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 2*a(n-1) + 20*a(n-2) - 19*a(n-3).
%F Empirical g.f.: 22*x*(1 + 20*x - 19*x^2) / (1 - 2*x - 20*x^2 + 19*x^3). - _Colin Barker_, Jul 07 2018
%e Some solutions for n=4:
%e ..0..1..1..1....0..1..1..0....0..1..1..0....0..1..0..0....0..1..0..1
%e ..0..1..0..1....1..1..0..1....0..1..0..1....0..1..0..1....0..1..0..1
%e ..1..1..1..1....0..1..0..0....0..1..1..0....1..1..0..0....1..1..1..1
%e ..0..1..0..1....1..1..0..0....1..1..0..0....0..1..0..0....0..1..0..1
%e ..1..1..0..1....0..1..0..0....0..1..0..0....0..1..1..1....1..1..1..1
%e ..0..1..1..1....1..1..1..0....0..1..1..0....0..1..0..0....0..1..0..1
%Y Cf. A208840.
%K nonn
%O 1,1
%A _R. H. Hardin_, Mar 01 2012
| 