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A232252
Number of (n+1)X(3+1) 0..2 arrays with every element both >= and <= some horizontal or antidiagonal neighbor
1
215, 6189, 175431, 4987471, 141815403, 4032714105, 114676900023, 3261035421093, 92733208328669, 2637030152019143, 74988542695581639, 2132429753296994177, 60639352262137170177, 1724385545471376948763, 49035904880139271370475
OFFSET
1,1
COMMENTS
Column 3 of A232257
LINKS
FORMULA
Empirical: a(n) = 27*a(n-1) +67*a(n-2) -667*a(n-3) -2143*a(n-4) -874*a(n-5) -67*a(n-6) +187*a(n-7) +95*a(n-8) +16*a(n-9) for n>10
EXAMPLE
Some solutions for n=3
..0..0..0..1....0..0..2..2....0..0..0..1....1..1..1..1....0..0..2..2
..1..1..2..2....2..2..1..1....0..2..2..2....1..1..1..2....0..2..0..0
..2..2..0..1....1..0..2..2....2..2..0..0....0..0..2..1....0..0..2..2
..2..0..1..1....0..1..2..2....1..1..0..0....0..1..0..0....1..1..1..1
CROSSREFS
Sequence in context: A137205 A091289 A085754 * A002239 A375180 A322929
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 21 2013
STATUS
approved