A272966 - OEIS

A272966

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.

%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