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A278408 Number of nX2 0..2 arrays with rows and columns in lexicographic nondecreasing order but with exactly two mistakes. 1
0, 20, 264, 2550, 22267, 166762, 1046418, 5586207, 25997719, 107862842, 406276442, 1409360487, 4554092377, 13832291491, 39781304005, 108983918717, 285829839116, 720662237189, 1752986235171, 4126404034476, 9424479791691, 20933182989114 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 2 of A278414.

LINKS

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

R. H. Hardin, Empirical polynomial of degree 26

FORMULA

Empirical polynomial of degree 26 (see link above)

EXAMPLE

Some solutions for n=4

..2..2. .1..1. .1..0. .0..0. .2..1. .2..0. .0..0. .2..0. .2..0. .2..1

..0..0. .0..1. .2..1. .1..0. .2..2. .0..0. .2..0. .2..1. .2..0. .2..1

..0..0. .1..2. .0..2. .2..1. .0..1. .0..0. .1..2. .0..1. .1..0. .0..2

..1..0. .0..0. .1..0. .1..1. .2..0. .1..1. .1..2. .2..0. .1..0. .2..0

CROSSREFS

Cf. A278414.

Sequence in context: A025943 A025961 A208948 * A229562 A021854 A025939

Adjacent sequences:  A278405 A278406 A278407 * A278409 A278410 A278411

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 21 2016

STATUS

approved

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Last modified December 4 02:40 EST 2021. Contains 349469 sequences. (Running on oeis4.)