A206536 Number of (n+1) X 3 0..2 arrays with the number of clockwise edge increases in 2 X 2 subblocks nondecreasing, and counterclockwise edge increases nonincreasing, rightwards and downwards.

399, 2577, 14781, 91674, 594348, 3902463, 25900263, 172835859, 1158343314, 7783336557, 52398118053, 353178544149, 2382554812068, 16081864446159, 108592014091443, 733452273626199, 4954756282052310, 33475276596812193

Offset

1,1

Comments

Column 2 of A206542.

Links

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

Formula

Empirical: a(n) = 14*a(n-1) -49*a(n-2) -96*a(n-3) +814*a(n-4) -820*a(n-5) -2734*a(n-6) +5904*a(n-7) +127*a(n-8) -8794*a(n-9) +6847*a(n-10) -336*a(n-11) -1164*a(n-12) +288*a(n-13) for n>17.

Example

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

Crossrefs

Sequence in context: A216925 A292573 A299213 * A292538 A369246 A065767

Adjacent sequences: A206533 A206534 A206535 * A206537 A206538 A206539

Keyword

nonn

Author

R. H. Hardin, Feb 09 2012

Status

approved