A198206 Number of 2nX4 0..3 arrays with values 0..3 introduced in row major order and each element unequal to exactly two horizontal and vertical neighbors

43, 1765, 50729, 1660672, 56315642, 1930887802, 66941645630, 2331298473193, 81407459944121, 2846734759084627, 99622031525717855, 3487698946608204322, 122128077706715335280, 4277023178407978272400, 149793878862653254021508

Offset

1,1

Comments

Column 2 of A198209

Links

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

Formula

Empirical: a(n) = 65*a(n-1) -1221*a(n-2) +4909*a(n-3) +38995*a(n-4) +97941*a(n-5) -5336901*a(n-6) +24513309*a(n-7) -24792291*a(n-8) +22615443*a(n-9) +29343465*a(n-10) -1299185649*a(n-11) +509455089*a(n-12) +6460607223*a(n-13) -508707135*a(n-14) -5208653241*a(n-15)

Example

Some solutions for n=3
..0..1..1..0....0..1..1..0....0..1..0..2....0..1..1..2....0..1..2..0
..2..2..2..2....2..0..0..2....2..1..0..1....2..3..3..1....3..1..2..2
..3..3..3..3....2..0..0..2....2..1..0..1....2..3..3..1....3..1..1..1
..2..2..2..2....3..3..3..0....0..1..0..0....0..1..1..2....0..0..0..0
..1..1..1..1....2..2..3..0....0..1..1..1....0..1..1..2....2..2..1..1
..0..2..2..3....1..2..3..2....3..0..0..2....1..0..0..1....0..2..1..0

Crossrefs

Sequence in context: A235646 A022220 A297028 * A162881 A163226 A163745

Adjacent sequences: A198203 A198204 A198205 * A198207 A198208 A198209

Keyword

nonn

Author

R. H. Hardin Oct 22 2011

Status

approved