A203970 Number of nX3 0..2 arrays with every 1 immediately preceded by 0 to the left or above, and every 2 immediately preceded by 0 1 to the left or above

4, 29, 258, 2061, 16723, 136243, 1107082, 9001543, 73188575, 595039791, 4837958263, 39334611930, 319806460796, 2600161056897, 21140392838611, 171880201142842, 1397457732946504, 11361914049797193, 92377098701406680

Offset

1,1

Comments

Column 3 of A203975

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +14*a(n-2) +134*a(n-3) +164*a(n-4) +465*a(n-5) -951*a(n-6) -633*a(n-7) -3451*a(n-8) +4286*a(n-9) +1728*a(n-10) +5640*a(n-11) -7916*a(n-12) -1912*a(n-13) -2947*a(n-14) +6073*a(n-15) +752*a(n-16) +143*a(n-17) -1899*a(n-18) +55*a(n-19) +89*a(n-20) +178*a(n-21) -5*a(n-22) -5*a(n-23) -5*a(n-24)

Example

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

Crossrefs

Sequence in context: A125808 A367752 A254124 * A250885 A369215 A244594

Adjacent sequences: A203967 A203968 A203969 * A203971 A203972 A203973

Keyword

nonn

Author

R. H. Hardin Jan 08 2012

Status

approved