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A204368
Number of (n+2) X 8 0..2 arrays with every 3 X 3 subblock having three equal elements in a row horizontally, vertically or nw-to-se diagonally exactly three ways, and new values 0..2 introduced in row major order.
1
6121, 4355, 2574, 2956, 3280, 4856, 9272, 19880, 50056, 132856, 356056, 968312, 2641688, 7207448, 19686232, 53780248, 146914840, 401373080, 1096568600, 2995854104, 8184818200, 22361337112, 61092259096, 166907144984, 455998800152
OFFSET
1,1
COMMENTS
Column 6 of A204370.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) -6*a(n-4) +4*a(n-6) for n>9.
Empirical g.f.: x*(6121 - 14008*x - 10491*x^2 - 4766*x^3 + 31138*x^4 + 21146*x^5 - 14336*x^6 - 7620*x^7 - 200*x^8) / ((1 - x)*(1 - 2*x - 2*x^2)*(1 - 2*x^3)). - Colin Barker, Jun 07 2018
EXAMPLE
Some solutions for n=5:
..0..1..2..0..1..0..1..2....0..1..0..0..1..1..0..0....0..0..1..2..1..2..2..2
..0..1..2..0..1..0..1..2....0..1..0..0..1..1..0..0....0..0..1..2..1..2..2..1
..0..1..2..0..1..0..1..2....0..1..0..0..1..1..0..0....0..0..1..2..1..2..2..1
..0..1..2..0..1..0..1..2....0..1..0..0..1..1..0..0....0..0..1..2..1..2..2..1
..0..1..2..0..1..0..1..2....0..1..0..0..1..1..0..0....0..0..1..2..1..2..2..1
..0..1..2..0..1..0..1..2....0..0..0..0..1..1..0..0....0..0..1..2..1..2..2..1
..0..1..2..0..1..0..1..2....2..1..0..0..1..1..0..0....0..0..1..2..1..2..2..1
CROSSREFS
Cf. A204370.
Sequence in context: A366516 A224483 A065695 * A114131 A144491 A184501
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 14 2012
STATUS
approved