%I #6 Apr 21 2020 12:54:28
%S 0,2,266,19750,1673658,251740932,90752836672,93037538287080,
%T 293564184229043556,2953569640505846392444
%N Number of n X n 0..1 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly two mistakes.
%C Diagonal of A278778.
%e Some solutions for n=4
%e ..1..0..0..0. .0..0..0..0. .1..0..0..1. .1..1..0..0. .0..0..1..0
%e ..1..1..0..1. .1..0..1..0. .1..1..1..1. .0..0..1..1. .1..0..0..0
%e ..1..1..0..1. .0..0..0..0. .0..0..0..0. .0..0..1..0. .0..0..0..0
%e ..1..0..0..0. .0..0..0..1. .1..1..1..0. .1..0..1..0. .0..0..1..1
%Y Cf. A278778.
%K nonn
%O 1,2
%A _R. H. Hardin_, Nov 28 2016