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A184122 Number of nX2 0..3 arrays with rows and columns in nondecreasing order 1
10, 86, 561, 2861, 12068, 43947, 142376, 419213, 1139569, 2894178, 6931366, 15770131, 34291532, 71619470, 144269412, 281284873, 532422712, 980922994, 1763049635, 3097467201, 5328692624, 8990408705, 14896447100, 24269860485 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A184129

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..200

FORMULA

Empirical: a(n)=16*a(n-1)-120*a(n-2)+560*a(n-3)-1820*a(n-4)+4368*a(n-5)-8008*a(n-6)+11440*a(n-7)-12870*a(n-8)+11440*a(n-9)-8008*a(n-10)+4368*a(n-11)-1820*a(n-12)+560*a(n-13)-120*a(n-14)+16*a(n-15)-a(n-16) (=polynomial of degree 15)

EXAMPLE

Some solutions for 3X2

..0..1....2..2....0..1....0..2....0..1....2..3....0..3....0..2....1..2....1..2

..0..1....2..2....2..0....1..3....3..0....2..3....2..3....1..2....2..0....1..2

..3..3....2..3....2..2....2..2....3..1....3..1....2..3....2..1....2..3....3..0

CROSSREFS

Sequence in context: A000454 A145146 A252981 * A228123 A163412 A287827

Adjacent sequences:  A184119 A184120 A184121 * A184123 A184124 A184125

KEYWORD

nonn

AUTHOR

R. H. Hardin Jan 09 2011

STATUS

approved

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Last modified December 12 17:50 EST 2019. Contains 329960 sequences. (Running on oeis4.)