A229639 Number of defective 3-colorings of a 3 X n 0..2 array connected horizontally, diagonally and antidiagonally with exactly two mistakes, and colors introduced in row-major 0..2 order.

0, 39, 244, 1109, 6031, 28448, 136778, 633328, 2905016, 13118016, 58633648, 259523840, 1139461984, 4967050352, 21516000592, 92679568016, 397212173264, 1694694809008, 7200709256752, 30481238674128, 128588345884944

Offset

1,2

Comments

Row 3 of A229637.

Links

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

Formula

Empirical: a(n) = 9*a(n-1) - 15*a(n-2) - 51*a(n-3) + 96*a(n-4) + 138*a(n-5) - 92*a(n-6) - 60*a(n-7) +4 8*a(n-8) - 8*a(n-9) for n > 12.

Example

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

Crossrefs

Sequence in context: A190538 A190606 A101627 * A070146 A372930 A327344

Adjacent sequences: A229636 A229637 A229638 * A229640 A229641 A229642

Keyword

nonn

Author

R. H. Hardin, Sep 27 2013

Status

approved