A268014 Number of n X 2 0..2 arrays with every repeated value in every row and column greater than or equal to the previous repeated value.

9, 81, 729, 6084, 49284, 386884, 2965284, 22268961, 164378041, 1195430625, 8581613769, 60904316944, 427872974400, 2978730810000, 20567785069584, 140966727989481, 959632952511249, 6492348190361881, 43674091151207841

Offset

1,1

Comments

Column 2 of A268019.

Links

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

Formula

Empirical: a(n) = 25*a(n-1) -225*a(n-2) +745*a(n-3) +475*a(n-4) -6275*a(n-5) -885*a(n-6) +22525*a(n-7) +22525*a(n-8) -885*a(n-9) -6275*a(n-10) +475*a(n-11) +745*a(n-12) -225*a(n-13) +25*a(n-14) -a(n-15).

Example

Some solutions for n=5
..1..1....0..2....2..1....1..1....1..1....1..0....0..2....1..0....1..0....2..1
..2..2....0..2....2..2....0..1....2..2....0..0....2..2....0..0....2..0....0..0
..0..1....1..0....2..0....1..1....1..1....2..2....0..1....1..0....0..1....0..2
..1..0....2..1....1..0....1..1....0..1....0..2....1..2....1..2....2..2....0..1
..0..2....2..0....2..0....2..0....1..0....1..2....0..0....0..0....2..0....0..2

Crossrefs

Cf. A268019.

Sequence in context: A174108 A254435 A267790 * A228972 A125947 A120997

Adjacent sequences: A268011 A268012 A268013 * A268015 A268016 A268017

Keyword

nonn

Author

R. H. Hardin, Jan 24 2016

Status

approved