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”).

A282125
Number of n X 2 0..2 arrays with no element unequal to more than four of its king-move neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.
1
0, 0, 30, 412, 4018, 35472, 296062, 2378276, 18602538, 142686584, 1078094998, 8049085452, 59514821186, 436531302624, 3180302488110, 23036382105332, 166033195371866, 1191480270802248, 8517590180994246, 60683797705011932
OFFSET
1,3
LINKS
FORMULA
Empirical: a(n) = 14*a(n-1) - 57*a(n-2) + 88*a(n-3) - 256*a(n-4) + 240*a(n-5) - 320*a(n-6) + 256*a(n-7) - 64*a(n-8).
Empirical g.f.: 2*x^3*(3 - 2*x + 4*x^2)*(5 + 2*x - 12*x^2) / (1 - 7*x + 4*x^2 - 16*x^3 + 8*x^4)^2. - Colin Barker, Feb 20 2019
EXAMPLE
Some solutions for n=4:
..0..0. .0..1. .0..1. .0..1. .0..0. .0..0. .0..1. .0..0. .0..1. .0..0
..0..1. .0..1. .0..1. .1..1. .1..2. .1..2. .0..2. .1..0. .0..2. .1..0
..2..0. .2..1. .0..2. .1..0. .2..2. .2..2. .0..0. .2..1. .1..1. .0..0
..1..2. .0..1. .0..1. .2..1. .2..0. .0..0. .0..2. .1..1. .2..2. .2..0
CROSSREFS
Column 2 of A282130.
Sequence in context: A010835 A022722 A278016 * A296917 A255002 A126922
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 06 2017
STATUS
approved