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

1,3

Comments

Column 2 of A278385.

Links

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

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.

Example

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

Crossrefs

Cf. A278385.

Sequence in context: A013286 A013291 A013292 * A181395 A165395 A165386

Adjacent sequences: A278376 A278377 A278378 * A278380 A278381 A278382

Keyword

nonn

Author

R. H. Hardin, Nov 20 2016

Status

approved