login
A232251
Number of (n+1) X (2+1) 0..2 arrays with every element both >= and <= some horizontal or antidiagonal neighbor.
2
37, 421, 4711, 52779, 591181, 6622029, 74175439, 830862931, 9306762101, 104248027381, 1167715590199, 13079956849787, 146512791834269, 1641136772671133, 18382899355702175, 205912751666562211
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 10*a(n-1) + 14*a(n-2) - 6*a(n-3) - a(n-4).
Empirical g.f.: x*(37 + 51*x - 17*x^2 - 3*x^3) / (1 - 10*x - 14*x^2 + 6*x^3 + x^4). - Colin Barker, Oct 03 2018
EXAMPLE
Some solutions for n=4:
..0..0..2....0..0..0....2..2..2....0..0..0....0..0..1....2..2..0....0..0..2
..0..2..1....0..0..2....0..0..0....1..2..1....1..2..2....0..0..1....0..2..2
..2..1..1....1..2..0....0..0..0....2..1..1....2..1..0....1..2..2....2..2..1
..1..2..1....2..0..0....1..2..2....1..0..0....0..0..2....0..0..1....0..0..1
..2..0..0....0..2..2....2..2..2....0..2..2....0..2..2....1..1..1....0..2..2
CROSSREFS
Column 2 of A232257.
Sequence in context: A083818 A090023 A254682 * A232259 A232046 A218376
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 21 2013
STATUS
approved