A229509 Number of defective 3-colorings of an n X 7 0..2 array connected diagonally and antidiagonally with exactly one mistake, and colors introduced in row-major 0..2 order.

0, 36864, 1617408, 66764736, 2591476416, 97662620160, 3594819388032, 130060929470976, 4641452248481280, 163824460625170944, 5730178115023705728, 198917197365436687872, 6861092028565088103552, 235357133324860943359488

Offset

1,2

Comments

Column 7 of A229510.

Links

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

Formula

Empirical: a(n) = 78*a(n-1) - 1287*a(n-2) - 35964*a(n-3) + 1117233*a(n-4) + 2786238*a(n-5) - 319372713*a(n-6) + 1257787440*a(n-7) + 44761084056*a(n-8) - 341244958320*a(n-9) - 3277644180408*a(n-10) + 38034583303392*a(n-11) + 107407886665608*a(n-12) - 2310987437840016*a(n-13) + 670615070938488*a(n-14) + 81246940478399232*a(n-15) - 175581039433630896*a(n-16) - 1642000043393779680*a(n-17) + 6047215760091910320*a(n-18) + 17688174604284225600*a(n-19) - 102577837211971196400*a(n-20) - 66593077133653908000*a(n-21) + 963194364822483846000*a(n-22) - 503839230173491680000*a(n-23) - 4917956815925112240000*a(n-24) + 6476674130582292000000*a(n-25) + 11618360328126193200000*a(n-26) - 25622007549556320000000*a(n-27) - 3568779622973916000000*a(n-28) + 35687796229739160000000*a(n-29) - 20589113209464900000000*a(n-30) for n > 31.

Example

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

Crossrefs

Cf. A229510.

Sequence in context: A251386 A175748 A204104 * A223304 A190383 A051393

Adjacent sequences: A229506 A229507 A229508 * A229510 A229511 A229512

Keyword

nonn

Author

R. H. Hardin, Sep 25 2013

Status

approved