A196648 Number of n X 3 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 3,4,0,2,1 for x=0,1,2,3,4.

2, 10, 27, 76, 248, 735, 2178, 6622, 20006, 60256, 181914, 549017, 1656115, 4996932, 15077683, 45492308, 137261044, 414152752, 1249599381, 3770345250, 11376066317, 34324394098, 103565135609, 312481530333, 942833738234, 2844761508741

Offset

1,1

Comments

Every 0 is next to 0 3's, every 1 is next to 1 4's, every 2 is next to 2 0's, every 3 is next to 3 2's, every 4 is next to 4 1's.

Column 3 of A196653.

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = 2*a(n-1) +a(n-2) +5*a(n-3) +a(n-4) +5*a(n-5) +9*a(n-6) +5*a(n-7) -3*a(n-8) -8*a(n-9) -14*a(n-11) -9*a(n-12) -2*a(n-13) +a(n-14) +2*a(n-15).

Example

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

Crossrefs

Cf. A196653.

Sequence in context: A133479 A196324 A327841 * A220700 A057753 A060515

Adjacent sequences: A196645 A196646 A196647 * A196649 A196650 A196651

Keyword

nonn

Author

R. H. Hardin, Oct 04 2011

Status

approved