login
A204283
Number of (n+2) X 9 0..2 arrays with every 3 X 3 subblock having three equal elements in a row horizontally, vertically, diagonally or antidiagonally exactly three ways, and new values 0..2 introduced in row major order.
1
29731, 1883, 1990, 1914, 2168, 2860, 3664, 6784, 15304, 36408, 95912, 258472, 698248, 1903432, 5196040, 14182920, 38742920, 105842056, 289142920, 789944968, 2158161544, 5896163976, 16108606088, 44009516680, 120236152456, 328491253384
OFFSET
1,1
COMMENTS
Column 7 of A204284.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) -6*a(n-4) +4*a(n-6) for n>8.
Empirical g.f.: x*(29731 - 87310*x - 3659*x^2 - 4056*x^3 + 174812*x^4 + 7654*x^5 - 111900*x^6 - 256*x^7) / ((1 - x)*(1 - 2*x - 2*x^2)*(1 - 2*x^3)). - Colin Barker, Jun 06 2018
EXAMPLE
Some solutions for n=4:
..0..1..0..2..1..2..2..1..1....0..0..0..0..0..0..0..0..0
..0..1..0..2..1..2..2..1..1....0..0..0..0..0..0..0..0..0
..0..1..0..2..1..2..2..1..1....1..1..1..1..1..1..1..1..1
..0..1..0..2..1..2..2..1..1....1..1..1..1..1..1..1..1..1
..0..1..0..2..1..2..2..1..1....2..2..2..2..2..2..2..2..2
..0..1..0..2..1..2..2..1..1....1..1..1..1..1..1..1..1..1
CROSSREFS
Cf. A204284.
Sequence in context: A203502 A228544 A206203 * A251054 A206070 A056747
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 13 2012
STATUS
approved