A208387 Number of nX3 0..2 arrays with new values 0..2 introduced in row major order and no element equal to more than two of its immediate leftward or upward or right-upward antidiagonal neighbors

5, 117, 3042, 79092, 2056392, 53466192, 1390120992, 36143145792, 939721790592, 24432766555392, 635251930440192, 16516550191444992, 429430304977569792, 11165187929416814592, 290294886164837179392, 7547667040285766664192

Offset

1,1

Comments

Column 3 of A208392

Links

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

Formula

Empirical: a(n) = 26*a(n-1) for n>2

Example

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

Crossrefs

Sequence in context: A268606 A006221 A265977 * A144998 A257865 A212040

Adjacent sequences: A208384 A208385 A208386 * A208388 A208389 A208390

Keyword

nonn

Author

R. H. Hardin Feb 25 2012

Status

approved