%I #5 Apr 21 2020 12:37:44
%S 1,6,12,8,4,8,4,8
%N Number of n X n 0..1 arrays with exactly n+n-2 having value 1 and no three 1's forming an isosceles triangle.
%C Diagonal of A272973.
%e Some solutions for n=3
%e ..1..1..0. .1..0..1. .0..0..1. .0..1..1. .0..1..1. .1..0..0. .1..0..0
%e ..0..0..0. .1..0..1. .1..0..1. .0..0..0. .0..0..0. .1..0..0. .1..0..1
%e ..1..1..0. .0..0..0. .1..0..0. .0..1..1. .1..1..0. .0..1..1. .0..0..1
%Y Cf. A272973.
%K nonn
%O 1,2
%A _R. H. Hardin_, May 11 2016