A221830 Number of 3Xn arrays of occupancy after each element moves to some horizontal, vertical or antidiagonal neighbor, without 2-loops or left turns

0, 14, 202, 2879, 40983, 583419, 8304016, 118195328, 1682332699, 23945477164, 340827864824, 4851172222091, 69049142818994, 982810732310121, 13988833113623959, 199110007092542464, 2834031588079597413

Offset

1,2

Comments

Row 3 of A221828

Links

R. H. Hardin, Table of n, a(n) for n = 1..184

Formula

Empirical: a(n) = 17*a(n-1) -39*a(n-2) -14*a(n-3) +134*a(n-4) -161*a(n-5) +50*a(n-6) -147*a(n-7) +129*a(n-8) +215*a(n-9) -131*a(n-10) +53*a(n-11) -92*a(n-12) -97*a(n-13) +31*a(n-14) -27*a(n-15) +16*a(n-16) +6*a(n-17) for n>18

Example

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

Crossrefs

Sequence in context: A051817 A199707 A222586 * A068769 A113349 A109764

Adjacent sequences: A221827 A221828 A221829 * A221831 A221832 A221833

Keyword

nonn

Author

R. H. Hardin Jan 26 2013

Status

approved