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A223976
Number of 3Xn 0..2 arrays with rows and antidiagonals unimodal
1
27, 729, 9515, 76092, 440628, 2026448, 7829639, 26375691, 79507149, 218578373, 555979549, 1323191288, 2972776392, 6350443334, 12975277251, 25482263325, 48302292951, 88682057873, 158180868607, 274824912452, 466153399196
OFFSET
1,1
COMMENTS
Row 3 of A223975
LINKS
FORMULA
Empirical: a(n) = (5051/239500800)*n^12 + (17911/39916800)*n^11 + (132833/21772800)*n^10 + (35869/725760)*n^9 + (2045741/7257600)*n^8 + (425867/403200)*n^7 + (62493899/21772800)*n^6 + (727483/145152)*n^5 + (33993559/5443200)*n^4 + (2107249/907200)*n^3 + (3822521/831600)*n^2 + (49331/13860)*n + 1
EXAMPLE
Some solutions for n=3
..1..2..0....1..2..2....1..2..0....0..1..2....2..0..0....2..2..0....2..0..0
..1..0..0....0..2..2....2..2..1....0..2..2....1..1..1....0..1..2....2..1..0
..2..1..0....0..1..1....0..2..2....1..2..2....0..1..1....2..0..0....2..2..1
CROSSREFS
Sequence in context: A073537 A016947 A223790 * A167726 A268022 A223571
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 30 2013
STATUS
approved