A278379 Number of n X 2 0..1 arrays with rows and columns in lexicographic nondecreasing order but with exactly three mistakes.

0, 0, 3, 40, 267, 1350, 5936, 23565, 84912, 278422, 835824, 2316601, 5980937, 14503972, 33282396, 72732358, 152195016, 306378420, 595704701, 1122541470, 2056128263, 3670127802, 6398217740, 10915088955, 18252749400, 29965289850

Offset: 1

Author

R. H. Hardin, Nov 20 2016

Keywords

• nonn

Comments

Column 2 of A278385.

Examples

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

Links

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

Crossrefs

Cf. A278385.

Formula

Empirical: a(n) = (1/1307674368000)*n^15 + (1/12454041600)*n^14 + (149/37362124800)*n^13 + (31/319334400)*n^12 + (1517/1306368000)*n^11 + (169/87091200)*n^10 - (73537/1828915200)*n^9 - (3971/87091200)*n^8 + (2939219/653184000)*n^7 + (521/2419200)*n^6 - (1516673/44906400)*n^5 - (19007/59875200)*n^4 + (351393113/4540536000)*n^3 + (3149/21621600)*n^2 - (5/104)*n.