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A219580
Number of 3 X n arrays of the minimum value of corresponding elements and their horizontal or vertical neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..3 3 X n array.
1
10, 59, 415, 1866, 7036, 24679, 82431, 262218, 794994, 2306682, 6437512, 17356645, 45369595, 115310672, 285657785, 691223503, 1636760443, 3798648663, 8652302302, 19363687067, 42621048296, 92344502687, 197095580897, 414682113414
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = (1/33607621760550469632000000)*n^26 - (1/484725313854093312000000)*n^25 - (1/51704033477769953280000)*n^24 + (1031/77556050216654929920000)*n^23 - (17779/22480014555552153600000)*n^22 + (1651/117902174242406400000)*n^21 + (2759/3096420737679360000)*n^20 - (2518541/38318206628782080000)*n^19 + (19230307/9778170750566400000)*n^18 - (838393657/40334954346086400000)*n^17 - (3591217757/6959756828344320000)*n^16 + (261879931739/10439635242516480000)*n^15 - (131492040123481/301589462561587200000)*n^14 + (111804541353067/52198176212582400000)*n^13 + (137552448921647/1739939207086080000)*n^12 - (1172825003674573/474528874659840000)*n^11 + (6687445020633329/152783917977600000)*n^10 - (230249703336413699/387836099481600000)*n^9 + (3849062585520497797/580578888314880000)*n^8 - (191742150641745613753/3193183885731840000)*n^7 + (61494391364509619939057/146354261429376000000)*n^6 - (24715893106541633240971/12196188452448000000)*n^5 + (16393875791749628685187/3740164458750720000)*n^4 + (616379400791599630243/31168037156256000)*n^3 - (80004272367965828689/385889983839360)*n^2 + (20031432765115703/26771144400)*n - 1070722 for n > 10.
EXAMPLE
Some solutions for n=3:
..0..0..0....2..1..1....2..0..0....2..1..0....1..0..0....1..0..0....3..0..0
..1..0..0....2..2..1....0..0..0....2..0..0....0..0..0....3..1..0....3..2..0
..1..1..2....2..2..2....3..0..0....3..1..0....3..0..2....3..3..2....3..2..2
CROSSREFS
Row 3 of A219578.
Sequence in context: A055586 A326827 A054489 * A267021 A213346 A140890
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 23 2012
STATUS
approved