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A224137
Number of 6 X n 0..1 arrays with rows nondecreasing and antidiagonals unimodal.
1
64, 729, 2692, 6392, 12874, 24095, 42832, 72888, 119424, 189263, 291226, 436500, 639038, 915991, 1288172, 1780552, 2422788, 3249783, 4302278, 5627476, 7279698, 9321071, 11822248, 14863160, 18533800, 22935039, 28179474, 34392308, 41712262
OFFSET
1,1
COMMENTS
Row 6 of A224133.
LINKS
FORMULA
Empirical: a(n) = (2/45)*n^6 + (8/15)*n^5 + (181/36)*n^4 + 28*n^3 + (19247/180)*n^2 + (3952/15)*n - 120 for n>4.
Conjectures from Colin Barker, Aug 27 2018: (Start)
G.f.: x*(64 + 281*x - 1067*x^2 + 617*x^3 + 1387*x^4 - 1840*x^5 + 160*x^6 + 696*x^7 - 172*x^8 - 154*x^9 + 60*x^10) / (1 - x)^7.
a(n) = 7*a(n-1) - 21*a(n-2) + 35*a(n-3) - 35*a(n-4) + 21*a(n-5) - 7*a(n-6) + a(n-7) for n>11.
(End)
EXAMPLE
Some solutions for n=3:
..0..0..1....0..0..1....0..1..1....0..0..1....0..0..0....0..0..0....0..0..1
..1..1..1....0..1..1....0..0..1....0..0..0....0..0..0....0..1..1....0..1..1
..0..1..1....1..1..1....0..0..1....0..0..1....0..1..1....0..0..1....0..1..1
..0..1..1....0..0..1....0..1..1....0..0..0....1..1..1....0..0..0....1..1..1
..1..1..1....0..1..1....0..0..1....0..0..1....1..1..1....0..0..1....1..1..1
..0..0..0....0..1..1....0..0..1....0..0..0....0..0..1....0..0..1....0..1..1
CROSSREFS
Cf. A224133.
Sequence in context: A161860 A195249 A223953 * A016899 A250364 A346638
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 31 2013
STATUS
approved