cp's OEIS Frontend

A207780 Number of n X n 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 0 and 1 0 1 vertically.

%I A207780 #9 Jul 22 2025 20:50:14
%S A207780 2,16,98,791,6766,65094,786907,9855231,142116676,2459545057,
%T A207780 46309750425,999589825419,26202502382134,768926273969151,
%U A207780 25878896800392858,1098191860946291476,52205734467966457603,2867736141204451650414
%N A207780 Number of n X n 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 0 and 1 0 1 vertically.
%C A207780 Diagonal of A207785
%H A207780 R. H. Hardin, <a href="/A207780/b207780.txt">Table of n, a(n) for n = 1..19</a>
%e A207780 Some solutions for n=4
%e A207780 ..0..0..1..0....1..0..0..1....0..1..0..1....1..1..1..1....1..0..1..0
%e A207780 ..0..1..0..0....0..1..0..1....0..1..0..1....1..1..1..1....1..1..0..1
%e A207780 ..1..0..0..1....0..0..1..0....1..0..1..0....1..1..1..1....0..1..0..1
%e A207780 ..1..0..1..0....1..0..1..0....1..0..1..0....1..1..1..0....0..0..1..0
%K A207780 nonn
%O A207780 1,1
%A A207780 _R. H. Hardin_ Feb 20 2012