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A205313
Number of (n+1) X 4 0..1 arrays with every 2 X 2 subblock having the same number of equal edges, and new values 0..1 introduced in row major order.
1
56, 376, 2606, 18152, 126536, 882182, 6150512, 42881096, 298965278, 2084374136, 14532174632, 101317751318, 706383387200, 4924877262824, 34336051065326, 239389600968776, 1669014906316040, 11636306448704678, 81127872049414160
OFFSET
1,1
COMMENTS
Column 3 of A205318.
LINKS
FORMULA
Empirical: a(n) = 10*a(n-1) -24*a(n-2) +21*a(n-3) -6*a(n-4).
Empirical g.f.: 2*x*(2 - 3*x)*(14 - 25*x + 10*x^2) / ((1 - x)*(1 - 9*x + 15*x^2 - 6*x^3)). - Colin Barker, Jun 11 2018
EXAMPLE
Some solutions for n=4:
..0..1..0..1....0..1..1..0....0..0..0..0....0..0..1..1....0..0..1..0
..1..1..1..1....1..1..0..0....0..1..1..0....0..1..1..0....0..1..1..1
..0..1..0..0....0..0..0..1....1..1..0..0....0..0..0..0....1..1..0..0
..0..0..0..1....0..1..1..1....1..0..0..1....0..1..1..0....1..0..0..1
..1..1..1..1....0..1..0..0....1..1..0..1....1..1..0..0....0..0..1..1
CROSSREFS
Cf. A205318.
Sequence in context: A181705 A219826 A075283 * A287702 A008447 A076647
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 25 2012
STATUS
approved