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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. 1
12, 1840, 6809, 15075, 29776, 57677, 113330, 228657, 473562, 1000381, 2139866, 4607729, 9947906, 21481485, 46333458, 99752209, 214296842, 459341309, 982407146, 2096608977, 4465367730, 9492005773, 20140323170, 42660619313 (list; graph; refs; listen; history; text; internal format)
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

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Last modified September 22 03:54 EDT 2020. Contains 337289 sequences. (Running on oeis4.)