A204973 Number of nX3 0..2 arrays with no occurrence of three equal elements in a row horizontally, vertically, diagonally or antidiagonally, and new values 0..2 introduced in row major order

4, 96, 1217, 16813, 226908, 3074889, 41618941, 563504926, 7628868673, 103284942785, 1398329242622, 18931424557397, 256304779809413, 3470006246394670, 46978999502038957, 636029536681800861

Offset

1,1

Comments

Column 3 of A204978

Links

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

Formula

Empirical: a(n) = 9*a(n-1) +79*a(n-2) -165*a(n-3) -1117*a(n-4) +1506*a(n-5) +4665*a(n-6) -8530*a(n-7) +2842*a(n-8) +16415*a(n-9) -52874*a(n-10) -90975*a(n-11) +139014*a(n-12) -2762*a(n-13) -188806*a(n-14) +657130*a(n-15) -216610*a(n-16) -282088*a(n-17) +299084*a(n-18) -320888*a(n-19) -25488*a(n-20) +130096*a(n-21) -166448*a(n-22) -3680*a(n-23) +14752*a(n-24) -23360*a(n-25) +12288*a(n-26) +6144*a(n-27)

Example

Some solutions for n=5
..0..1..2....0..0..1....0..1..0....0..0..1....0..1..1....0..0..1....0..0..1
..0..2..1....0..1..1....2..1..2....2..0..0....0..1..2....0..0..1....1..2..2
..1..2..0....2..2..0....2..2..1....2..1..2....2..2..0....1..1..2....2..1..2
..1..0..0....0..1..2....0..1..1....1..1..2....0..1..1....2..1..1....2..2..0
..2..2..1....0..1..1....0..0..2....1..2..0....0..2..1....0..0..2....0..1..1

Crossrefs

Sequence in context: A202682 A089639 A269091 * A204700 A267953 A206645

Adjacent sequences: A204970 A204971 A204972 * A204974 A204975 A204976

Keyword

nonn

Author

R. H. Hardin Jan 21 2012

Status

approved