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A224386 Number of nX3 0..3 arrays with diagonals and antidiagonals unimodal and rows nondecreasing 1
20, 400, 6094, 86701, 1268572, 18794636, 279128617, 4142692993, 61481903024, 912523782542, 13544525098266, 201041292342421, 2984053971336637, 44292278131103241, 657430060365000621, 9758232360460992934 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A224391

LINKS

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

FORMULA

Empirical: a(n) = 20*a(n-1) -70*a(n-2) -211*a(n-3) +2453*a(n-4) -12192*a(n-5) +5907*a(n-6) +119292*a(n-7) -294992*a(n-8) +742820*a(n-9) +144828*a(n-10) -5072952*a(n-11) +6034728*a(n-12) -15994872*a(n-13) -858096*a(n-14) -10368*a(n-15)

EXAMPLE

Some solutions for n=3

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

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

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

CROSSREFS

Sequence in context: A019319 A083276 A057745 * A189198 A224019 A171294

Adjacent sequences:  A224383 A224384 A224385 * A224387 A224388 A224389

KEYWORD

nonn

AUTHOR

R. H. Hardin Apr 05 2013

STATUS

approved

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Last modified January 27 12:01 EST 2020. Contains 331295 sequences. (Running on oeis4.)