A229752 Number of defective 4-colorings of an n X 5 0..3 array connected horizontally, vertically, diagonally and antidiagonally with exactly two mistakes, and colors introduced in row-major 0..3 order.

12, 1840, 6809, 15075, 29776, 57677, 113330, 228657, 473562, 1000381, 2139866, 4607729, 9947906, 21481485, 46333458, 99752209, 214296842, 459341309, 982407146, 2096608977, 4465367730, 9492005773, 20140323170, 42660619313

Offset

1,1

Links

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

Formula

Empirical: a(n) = 9*a(n-1) - 33*a(n-2) + 63*a(n-3) - 66*a(n-4) + 36*a(n-5) - 8*a(n-6) for n>11.

Empirical g.f.: x*(12 + 1732*x - 9355*x^2 + 13758*x^3 + 3670*x^4 - 20791*x^5 + 10370*x^6 + 686*x^7 - 1124*x^8 - 440*x^9 + 208*x^10) / ((1 - x)^3*(1 - 2*x)^3). - Colin Barker, Sep 21 2018

Example

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

Crossrefs

Column 5 of A229755.

Sequence in context: A090914 A049406 A049405 * A104009 A261946 A015028

Adjacent sequences: A229749 A229750 A229751 * A229753 A229754 A229755

Keyword

nonn

Author

R. H. Hardin, Sep 28 2013

Status

approved