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A188861
Number of n X 4 binary arrays without the pattern 0 1 diagonally, vertically or antidiagonally.
3
16, 41, 68, 95, 122, 149, 176, 203, 230, 257, 284, 311, 338, 365, 392, 419, 446, 473, 500, 527, 554, 581, 608, 635, 662, 689, 716, 743, 770, 797, 824, 851, 878, 905, 932, 959, 986, 1013, 1040, 1067, 1094, 1121, 1148, 1175, 1202, 1229, 1256, 1283, 1310, 1337, 1364
OFFSET
1,1
COMMENTS
Column 4 of A188866.
LINKS
FORMULA
Empirical: a(n) = 27*n - 13 for n>1.
Conjectures from Colin Barker, Feb 28 2018: (Start)
G.f.: x*(16 + 9*x + 2*x^2) / (1 - x)^2.
a(n) = 2*a(n-1) - a(n-2) for n>3.
(End)
EXAMPLE
Some solutions for 3 X 4:
..1..1..1..1....1..1..0..1....1..1..1..1....1..0..1..1....1..1..1..1
..1..1..1..1....0..0..0..0....1..1..1..0....0..0..0..0....0..0..1..0
..1..0..0..1....0..0..0..0....1..1..0..0....0..0..0..0....0..0..0..0
MATHEMATICA
Join[{16}, Range[41, 7000, 27]] (* Vladimir Joseph Stephan Orlovsky, Jul 13 2011 *)
CROSSREFS
Cf. A188866.
Sequence in context: A246344 A044093 A044474 * A134593 A227816 A200408
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 12 2011
STATUS
approved