A233172 Number of nX6 0..5 arrays with no element x(i,j) adjacent to itself or value 5-x(i,j) horizontally, diagonally or antidiagonally, top left element zero, and 1 appearing before 2 3 and 4, and 2 appearing before 3 in row major order (unlabelled 6-colorings with no clashing color pairs)

136, 92672, 76447744, 65265467392, 56275748519936, 48667983827959808, 42129429039341895680, 36480870847649836695552, 31592958742989872646062080, 27360904144981190573706706944, 23696028949244230878346703011840

Offset

1,1

Comments

Column 6 of A233174

Links

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

Formula

Empirical: a(n) = 1216*a(n-1) -303104*a(n-2) -6553600*a(n-3) +6056574976*a(n-4) -287762808832*a(n-5) -18622978195456*a(n-6) +1482141674242048*a(n-7) -15199648742375424*a(n-8) -522417556774977536*a(n-9) +5764607523034234880*a(n-10)

Example

Some solutions for n=2
..0..1..5..2..5..1....0..1..2..1..2..1....0..1..5..1..0..4....0..1..0..2..1..2
..5..2..5..3..0..2....5..1..5..1..5..4....5..1..0..2..5..1....5..1..0..2..1..2

Crossrefs

Sequence in context: A374308 A278185 A225832 * A233127 A157880 A233254

Adjacent sequences: A233169 A233170 A233171 * A233173 A233174 A233175

Keyword

nonn

Author

R. H. Hardin, Dec 05 2013

Status

approved