A278321 Number of nX4 0..1 arrays with rows and columns in lexicographic nondecreasing order but with exactly two mistakes.

1, 94, 1678, 19854, 186987, 1548002, 11947350, 87562135, 605431820, 3905165468, 23355599964, 129475795828, 667503759881, 3215875683718, 14555156486463, 62204964640341, 252211338710097, 974245904884957, 3598868691539578

Offset: 1

Author

R. H. Hardin, Nov 18 2016

Keywords

• nonn

Comments

Column 4 of A278325.

Examples

			Some solutions for n=4
..0..1..1..0. .1..1..0..0. .0..1..0..1. .0..1..0..1. .1..1..0..1
..1..0..1..1. .0..0..0..0. .0..1..1..1. .0..1..0..1. .1..1..0..1
..0..1..0..0. .1..1..1..1. .1..1..1..0. .0..0..0..0. .1..1..0..1
..1..1..0..1. .1..1..1..1. .0..1..1..1. .0..0..0..0. .0..0..1..1
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Crossrefs

Cf. A278325.

Formula

Empirical polynomial of degree 47 (see link above)