login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A233080
Number of n X 6 0..3 arrays with no element x(i,j) adjacent to value 3-x(i,j) horizontally or antidiagonally, top left element zero, and 1 appearing before 2 in row major order.
1
122, 32414, 8662343, 2315298290, 618844579511, 165407945648306, 44211082661517335, 11816964557611382642, 3158498796072853930295, 844219731401266443119474, 225647372661155279429241623
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 283*a(n-1) - 4251*a(n-2) + 13573*a(n-3) - 9604*a(n-4).
Empirical g.f.: x*(122 - 2112*x + 7803*x^2 - 8771*x^3) / ((1 - x)*(1 - 282*x + 3969*x^2 - 9604*x^3)). - Colin Barker, Oct 07 2018
EXAMPLE
Some solutions for n=2:
..0..1..0..0..2..0....0..0..1..1..3..3....0..1..3..2..2..2....0..1..0..2..0..1
..1..1..0..0..2..2....1..1..0..1..1..0....0..1..0..2..0..1....0..2..2..2..0..2
CROSSREFS
Column 6 of A233082.
Sequence in context: A209098 A233016 A282055 * A280678 A209105 A223131
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 03 2013
STATUS
approved