A229583 Number of defective 3-colorings of an n X 5 0..2 array connected horizontally and antidiagonally with exactly one mistake, and colors introduced in row-major 0..2 order.
16, 444, 9156, 167364, 2865780, 47091780, 752194836, 11768185764, 181223769204, 2756144066436, 41496027416532, 619575164338788, 9186393069102132, 135397538308042308, 1985403434065601940, 28983255427638399780
Offset: 1
Keywords
Examples
Some solutions for n=3: ..0..1..0..2..1....0..1..0..1..0....0..1..0..1..0....0..1..0..1..0 ..0..1..1..2..1....0..1..2..1..2....0..1..0..2..1....0..1..2..1..1 ..0..2..0..2..1....0..0..2..1..2....2..1..1..2..0....0..1..0..2..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Column 5 of A229586.
Formula
Empirical: a(n) = 30*a(n-1) - 261*a(n-2) + 540*a(n-3) - 324*a(n-4).
Empirical g.f.: 4*x*(4 - 9*x + 3*x^2 - 18*x^3) / (1 - 15*x + 18*x^2)^2. - Colin Barker, Sep 19 2018