A228972 Number of nX2 0..2 arrays of the median of the corresponding element, the element to the east and the element to the south in a larger (n+1)X3 0..2 array.

9, 81, 729, 6387, 55887, 488037, 4259277, 37155951, 324050745, 2825717151, 24637772289, 214806377331, 1872733313427, 16326535353843, 142332941107035, 1240830892976931, 10817256322467417, 94301798866919901, 822094581839055501

Offset

1,1

Comments

Column 2 of A228977.

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 13*a(n-1) -26*a(n-2) -122*a(n-3) +179*a(n-4) +248*a(n-5) -404*a(n-6) +135*a(n-7) +130*a(n-8) -374*a(n-9) +297*a(n-10) -120*a(n-11) +45*a(n-12).

Example

Some solutions for n=4
..2..0....1..0....1..0....2..0....2..1....0..2....2..2....2..1....0..1....0..0
..1..1....1..1....2..0....2..0....1..2....2..2....1..1....1..0....0..1....2..2
..1..2....2..1....0..0....2..1....1..2....1..0....2..0....1..1....2..0....0..0
..0..2....0..2....2..2....1..1....2..2....0..2....2..0....1..0....2..2....1..1

Crossrefs

Sequence in context: A254435 A267790 A268014 * A125947 A120997 A125630

Adjacent sequences: A228969 A228970 A228971 * A228973 A228974 A228975

Keyword

nonn

Author

R. H. Hardin, Sep 10 2013

Status

approved