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A207168
Number of n X 7 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 0 1 and 1 0 1 vertically
1
28, 784, 3808, 11452, 26908, 54208, 98224, 164668, 260092, 391888, 568288, 798364, 1092028, 1460032, 1913968, 2466268, 3130204, 3919888, 4850272, 5937148, 7197148, 8647744, 10307248, 12194812, 14330428, 16734928, 19429984, 22438108, 25782652
OFFSET
1,1
COMMENTS
Column 7 of A207169.
LINKS
FORMULA
Empirical: a(n) = 35*n^4 + 42*n^3 + 7*n^2 - 84*n + 28.
Conjectures from Colin Barker, Jun 20 2018: (Start)
G.f.: 28*x*(1 + 23*x + 6*x^2 - x^3 + x^4) / (1 - x)^5.
a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n>5.
(End)
EXAMPLE
Some solutions for n=4:
..0..1..0..0..1..1..0....1..0..0..1..0..0..1....0..0..1..0..0..1..1
..1..1..0..0..1..1..1....0..1..1..1..1..1..1....0..1..1..1..1..1..0
..1..1..0..0..1..1..1....0..1..1..1..0..0..1....0..0..1..0..0..1..0
..0..1..0..0..1..0..0....0..0..1..1..0..0..1....0..0..1..0..0..1..0
CROSSREFS
Cf. A207169.
Sequence in context: A207894 A207884 A207761 * A208012 A207789 A207304
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 15 2012
STATUS
approved