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%I #8 Oct 03 2025 05:35:39
%S 34,168,1135,12814,224705,5127157,154820497,6857389175,450847078335,
%T 41610167180266,5282145722452860,946058243422221058,
%U 244167133066656271715,89943772503552797451562
%N Number of (n+2)X(n+2) symmetric binary matrices without the pattern 1 0 1 diagonally, vertically, antidiagonally or horizontally.
%e Some solutions for 4X4
%e ..0..0..0..0....1..0..0..0....1..0..0..0....0..0..1..0....0..0..1..0
%e ..0..0..1..0....0..0..0..0....0..1..1..0....0..1..1..0....0..1..1..1
%e ..0..1..0..0....0..0..0..1....0..1..1..1....1..1..1..0....1..1..1..1
%e ..0..0..0..0....0..0..1..1....0..0..1..0....0..0..0..1....0..1..1..0
%K nonn
%O 1,1
%A _R. H. Hardin_, May 13 2011