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A208710 Number of 3 X n 0..1 arrays with new values 0..1 introduced in row major order and no element equal to more than two of its immediate leftward or upward or right-upward antidiagonal neighbors. 1
4, 32, 196, 1268, 8128, 52184, 334948, 2149988, 13800400, 88582472, 568596052, 3649722932, 23426960800, 150373741496, 965223885508, 6195610615940, 39768587869168, 255267911291816, 1638522010126516, 10517398618896212 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Row 3 of A208709.
LINKS
FORMULA
Empirical: a(n) = 5*a(n-1) + 9*a(n-2) + a(n-3) - 2*a(n-4).
Empirical g.f.: 4*x*(1 + 3*x - x^3) / ((1 + x)*(1 - 6*x - 3*x^2 + 2*x^3)). - Colin Barker, Jul 06 2018
EXAMPLE
Some solutions for n=4:
0 0 0 1 0 0 1 0 0 1 0 1 0 1 1 0 0 0 1 0
0 1 0 1 0 0 1 1 0 1 0 0 1 0 0 1 1 1 1 0
1 0 0 1 1 0 0 0 0 1 1 0 1 0 1 1 0 1 0 0
CROSSREFS
Cf. A208709.
Sequence in context: A270178 A018215 A099133 * A043018 A270015 A271161
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 01 2012
STATUS
approved

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Last modified April 13 20:16 EDT 2024. Contains 371645 sequences. (Running on oeis4.)