A229640 Number of defective 3-colorings of a 4 X n 0..2 array connected horizontally, diagonally and antidiagonally with exactly two mistakes, and colors introduced in row-major 0..2 order.
0, 202, 1496, 10227, 77620, 535671, 3723370, 25022190, 166505166, 1090285513, 7066637900, 45333775056, 288422981684, 1821192582307, 11424271291526, 71241698297248, 441922120307156, 2728236364222397, 16770150954151850
Offset: 1
Keywords
Examples
Some solutions for n=3: 0 1 0 0 1 1 0 0 1 0 1 1 0 0 1 0 1 1 0 1 0 1 2 2 0 2 1 2 0 1 1 2 0 2 0 2 2 0 2 0 2 2 1 0 1 0 2 1 2 0 2 0 2 1 2 0 2 2 0 1 1 2 1 1 0 2 1 2 1 1 0 1 0 2 1 1 0 1 2 0 2 1 2 1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = 9*a(n-1) + 21*a(n-2) - 270*a(n-3) - 357*a(n-4) + 2967*a(n-5) + 4906*a(n-6) - 10083*a(n-7) - 18957*a(n-8) + 15750*a(n-9) + 31293*a(n-10) - 13335*a(n-11) - 23929*a(n-12) + 6426*a(n-13) + 7824*a(n-14) - 1336*a(n-15) - 1152*a(n-16) + 96*a(n-17) + 64*a(n-18) for n > 21.
Comments