A278547 Number of n X 1 0..3 arrays with rows and columns in lexicographic nondecreasing order but with exactly two mistakes.

0, 0, 4, 65, 456, 2128, 7728, 23607, 63460, 154518, 347568, 732524, 1461824, 2784600, 5095376, 9002010, 15418728, 25691420, 41763900, 66395595, 103443144, 158220680, 237956160, 352364025, 514357740, 740929410, 1054227720, 1482869934

Offset

1,3

Comments

Column 1 of A278553.

Links

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

Formula

Empirical: a(n) = (1/39916800)*n^11 + (1/604800)*n^10 + (1/20736)*n^9 + (5/8064)*n^8 + (553/172800)*n^7 - (97/28800)*n^6 - (25591/725760)*n^5 + (89/24192)*n^4 + (13607/129600)*n^3 - (47/50400)*n^2 - (289/3960)*n.

Empirical g.f.: x^3*(4 + 17*x - 60*x^2 + 66*x^3 - 32*x^4 + 6*x^5) / (1 - x)^12. - Colin Barker, Mar 22 2018

Example

Some solutions for n=4:
..3. .0. .2. .2. .2. .3. .3. .1. .2. .2. .2. .3. .3. .2. .3. .2
..1. .2. .0. .1. .1. .2. .1. .0. .1. .1. .0. .2. .0. .0. .1. .3
..1. .1. .3. .2. .3. .0. .3. .2. .0. .0. .2. .0. .3. .3. .0. .2
..0. .0. .1. .0. .1. .1. .2. .0. .1. .3. .0. .2. .2. .2. .2. .0

Crossrefs

Cf. A278553.

Sequence in context: A058438 A171959 A041119 * A293562 A331577 A307169

Adjacent sequences: A278544 A278545 A278546 * A278548 A278549 A278550

Keyword

nonn

Author

R. H. Hardin, Nov 23 2016

Status

approved