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%I #9 Dec 18 2015 18:18:39
%S 1,3,39,780,43862,4823826,1316714732,762713002760,1040109467257908,
%T 3118624187066762728,21501868781585259257676,
%U 331091404725670052219822756,11603262095526618070600084170304,914315533886530112431287075923892544
%N Number of n X n binary arrays with top left element equal to 1 and no two ones adjacent horizontally or antidiagonally.
%C Diagonal of A228754
%H R. H. Hardin, <a href="/A228749/b228749.txt">Table of n, a(n) for n = 1..30</a>
%e Some solutions for n=4
%e ..1..0..0..0....1..0..0..1....1..0..0..0....1..0..1..0....1..0..0..0
%e ..1..0..0..0....0..1..0..0....0..0..0..1....0..0..1..0....1..0..1..0
%e ..0..1..0..1....0..0..0..1....0..1..0..0....1..0..0..1....1..0..1..0
%e ..0..1..0..0....1..0..0..0....0..1..0..1....0..0..0..0....1..0..0..0
%K nonn
%O 1,2
%A _R. H. Hardin_ Sep 02 2013