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A231397
Number of (1+1) X (n+1) 0..2 arrays with no element unequal to a strict majority of its horizontal, diagonal and antidiagonal neighbors, with values 0..2 introduced in row major order.
1
3, 7, 14, 33, 78, 189, 482, 1225, 3238, 8565, 23114, 62657, 171342, 470573, 1297330, 3586745, 9934454, 27559269, 76525210, 212662577, 591289630, 1644693789, 4576035586, 12734509097, 35443628358, 98659578197, 274645954794
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 4*a(n-1) + a(n-2) - 16*a(n-3) + 4*a(n-4) + 24*a(n-5) - 16*a(n-6).
Empirical g.f.: x*(3 - 5*x - 17*x^2 + 18*x^3 + 32*x^4 - 32*x^5) / ((1 - x)*(1 - 2*x)*(1 - x - 6*x^2 + 8*x^4)). - Colin Barker, Sep 28 2018
EXAMPLE
Some solutions for n=5:
..0..1..1..1..1..2....0..1..0..1..0..0....0..0..1..1..0..0....0..0..1..1..0..0
..0..0..1..1..2..2....1..0..1..0..1..1....0..0..1..1..1..0....0..0..1..1..0..0
CROSSREFS
Row 1 of A231396.
Sequence in context: A354603 A089526 A261051 * A231464 A146920 A079939
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 08 2013
STATUS
approved