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A278548
Number of nX2 0..3 arrays with rows and columns in lexicographic nondecreasing order but with exactly two mistakes.
1
0, 70, 1531, 25402, 385040, 4880813, 50476458, 435272199, 3222371162, 21002624643, 122940347621, 656384657007, 3235421775340, 14866063786408, 64169850484506, 261881056692205, 1015819011059751, 3761887253493383
OFFSET
1,2
COMMENTS
Column 2 of A278553.
FORMULA
Empirical polynomial of degree 47 (see link above)
EXAMPLE
Some solutions for n=4
..3..0. .3..0. .0..0. .0..1. .1..3. .1..3. .2..3. .2..1. .1..1. .2..2
..3..2. .2..2. .2..2. .2..3. .3..3. .1..1. .3..1. .2..2. .2..1. .3..2
..1..0. .3..1. .3..2. .2..1. .2..3. .3..3. .3..0. .2..3. .0..0. .0..3
..1..2. .3..2. .2..2. .1..3. .0..2. .2..2. .1..3. .2..1. .2..3. .1..2
CROSSREFS
Cf. A278553.
Sequence in context: A061606 A331351 A298973 * A107421 A076430 A006296
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 23 2016
STATUS
approved