cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A229586 T(n,k) = number of defective 3-colorings of an n X k 0..2 array connected horizontally and antidiagonally with exactly one mistake, and colors introduced in row-major 0..2 order.

Original entry on oeis.org

0, 1, 0, 2, 6, 0, 6, 28, 40, 0, 16, 116, 264, 224, 0, 40, 444, 1620, 2160, 1152, 0, 96, 1620, 9156, 19764, 16416, 5632, 0, 224, 5724, 49848, 167364, 224532, 119232, 26624, 0, 512, 19764, 264300, 1375152, 2865780, 2440692, 839808, 122880, 0, 1152, 67068, 1374048
Offset: 1

Views

Author

R. H. Hardin, Sep 26 2013

Keywords

Comments

Table starts
.0......1.......2.........6..........16...........40.............96
.0......6......28.......116.........444.........1620...........5724
.0.....40.....264......1620........9156........49848.........264300
.0....224....2160.....19764......167364......1375152.......11035044
.0...1152...16416....224532.....2865780.....35690460......435326724
.0...5632..119232...2440692....47091780....890824020....16551428868
.0..26624..839808..25745364...752194836..21639043284...613195191972
.0.122880.5785344.265720500.11768185764.515235810840.22285439501940

Examples

			Some solutions for n=3, k=4:
  0 1 2 1     0 0 1 2     0 1 2 0     0 1 0 1     0 1 2 0
  0 1 2 0     1 2 0 2     0 2 1 2     0 2 0 0     0 0 2 0
  1 0 2 0     0 2 0 1     1 2 1 0     0 1 2 0     2 0 2 0
		

Crossrefs

Row 1 is A057711(n-1).

Formula

Empirical for column k:
k=1: a(n) = a(n-1).
k=2: a(n) = 8*a(n-1) - 16*a(n-2) for n > 3.
k=3: a(n) = 12*a(n-1) - 36*a(n-2).
k=4: a(n) = 18*a(n-1) - 81*a(n-2) for n > 3.
k=5: a(n) = 30*a(n-1) - 261*a(n-2) + 540*a(n-3) - 324*a(n-4).
k=6: a(n) = 50*a(n-1) - 805*a(n-2) + 4662*a(n-3) - 12150*a(n-4) + 14580*a(n-5) - 6561*a(n-6).
k=7: [order 8]
Empirical for row n:
n=1: a(n) = 4*a(n-1) - 4*a(n-2) for n > 4.
n=2: a(n) = 6*a(n-1) - 9*a(n-2) for n > 4.
n=3: a(n) = 10*a(n-1) - 29*a(n-2) + 20*a(n-3) - 4*a(n-4) for n > 6.
n=4: [order 6] for n > 12.
n=5: [order 14] for n > 18.
n=6: [order 18] for n > 26.
n=7: [order 54] for n > 60.