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A223920 Number of 3Xn 0..2 arrays with rows and antidiagonals unimodal and columns nondecreasing 1
10, 100, 666, 3311, 13347, 45988, 140236, 387671, 988447, 2354539, 5291652, 11307388, 23115717, 45438234, 86243127, 158615577, 283521156, 493809754, 839915122, 1397838161, 2280164963, 3651068140, 5746477482, 8900889311 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 3 of A223918

LINKS

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

FORMULA

Empirical: a(n) = (1/19160064)*n^12 + (5/3193344)*n^11 + (1627/43545600)*n^10 + (257/483840)*n^9 + (2309/414720)*n^8 + (19319/483840)*n^7 + (8701321/43545600)*n^6 + (971137/1451520)*n^5 + (3369229/2177280)*n^4 + (294809/120960)*n^3 + (652717/237600)*n^2 + (521/385)*n + 1

EXAMPLE

Some solutions for n=3

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

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

..2..2..1....1..2..2....1..2..2....2..2..2....1..2..2....1..1..2....1..1..2

CROSSREFS

Sequence in context: A208074 A092707 A224263 * A223865 A293890 A218269

Adjacent sequences:  A223917 A223918 A223919 * A223921 A223922 A223923

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 29 2013

STATUS

approved

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Last modified January 27 10:00 EST 2022. Contains 350607 sequences. (Running on oeis4.)