A199144 Number of nX3 0..3 arrays with values 0..3 introduced in row major order and each element equal to one or two horizontal and vertical neighbors

1, 13, 132, 2453, 42420, 794416, 14511531, 268456338, 4940928443, 91146218920, 1679743067872, 30969409565822, 570877041856787, 10524153072061784, 194006638767664141, 3576453618832667684, 65930406443303698229

Offset

1,2

Comments

Column 3 of A199149

Links

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

Formula

Empirical: a(n) = 14*a(n-1) +120*a(n-2) -646*a(n-3) -1320*a(n-4) +3562*a(n-5) +12682*a(n-6) +1896*a(n-7) -76623*a(n-8) +36670*a(n-9) +19724*a(n-10) -245388*a(n-11) +53233*a(n-12) +2738818*a(n-13) -138967*a(n-14) -11411168*a(n-15) +3626519*a(n-16) +17979294*a(n-17) -10633666*a(n-18) -27553810*a(n-19) +19090457*a(n-20) +20077526*a(n-21) -32139160*a(n-22) +46609580*a(n-23) +115127457*a(n-24) +146403730*a(n-25) +50426678*a(n-26) -122760336*a(n-27) -143444310*a(n-28) -587979162*a(n-29) -679787397*a(n-30) -166474764*a(n-31) -212565465*a(n-32) +6372918*a(n-33) +256248603*a(n-34) +47278566*a(n-35) -708588*a(n-36) -12754584*a(n-37) for n>38

Example

Some solutions for n=4
..0..1..1....0..1..1....0..1..1....0..0..0....0..1..1....0..0..1....0..0..0
..0..1..2....0..0..0....0..2..0....0..1..1....0..2..2....2..2..1....1..1..0
..3..3..2....2..2..0....2..2..0....2..3..2....1..0..3....1..1..0....0..0..1
..1..1..1....3..3..3....2..0..0....2..3..2....1..0..3....2..2..0....0..1..1

Crossrefs

Sequence in context: A037715 A037617 A295603 * A198664 A332243 A081042

Adjacent sequences: A199141 A199142 A199143 * A199145 A199146 A199147

Keyword

nonn

Author

R. H. Hardin Nov 03 2011

Status

approved