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A278650
Number of nX2 0..2 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly three mistakes.
1
0, 0, 24, 1076, 19893, 235446, 2080575, 14836233, 89504692, 471646066, 2221297222, 9512455863, 37536099773, 137924875200, 475940969064, 1553081484256, 4820235461752, 14298088612192, 40701436072216, 111582345485761
OFFSET
1,3
COMMENTS
Column 2 of A278656.
FORMULA
Empirical polynomial of degree 33 (see link above)
EXAMPLE
Some solutions for n=4
..1..1. .0..0. .0..2. .1..1. .2..2. .2..2. .1..2. .1..2. .2..2. .0..2
..0..2. .1..2. .0..1. .0..2. .1..1. .2..0. .0..2. .0..2. .2..0. .2..2
..1..2. .1..0. .2..1. .1..2. .0..1. .1..1. .0..0. .2..1. .1..0. .1..2
..1..1. .0..1. .2..0. .0..0. .1..1. .0..1. .0..0. .2..0. .0..1. .0..1
CROSSREFS
Cf. A278656.
Sequence in context: A272690 A112011 A112010 * A046906 A130552 A374885
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 25 2016
STATUS
approved