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A223928 Number of nX3 0..2 arrays with rows, columns and antidiagonals unimodal and diagonals nondecreasing 1
22, 218, 1116, 4498, 15791, 49646, 142177, 375777, 926559, 2150622, 4734429, 9947574, 20054339, 38965176, 73242344, 133617438, 237234842, 410906947, 695757399, 1153741182, 1876668923, 2998531806, 4712127751, 7291234403 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A223933

LINKS

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

FORMULA

Empirical: a(n) = (1/19160064)*n^12 + (1/1064448)*n^11 + (1387/43545600)*n^10 + (577/1451520)*n^9 + (2717/414720)*n^8 + (10553/483840)*n^7 + (13338121/43545600)*n^6 + (19135/32256)*n^5 + (9514387/2177280)*n^4 + (1557389/362880)*n^3 + (1225691/118800)*n^2 + (1887533/27720)*n - 124 for n>3

EXAMPLE

Some solutions for n=3

..0..0..0....0..0..0....0..0..0....1..0..0....0..1..1....1..1..0....0..1..0

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

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

CROSSREFS

Sequence in context: A126543 A232019 A224330 * A224052 A224305 A224369

Adjacent sequences:  A223925 A223926 A223927 * A223929 A223930 A223931

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 29 2013

STATUS

approved

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Last modified September 25 22:02 EDT 2020. Contains 337344 sequences. (Running on oeis4.)