A204680 Number of nX3 0..3 arrays with no occurrence of three equal elements in a row horizontally, vertically, diagonally or antidiagonally, and new values 0..3 introduced in row major order

4, 159, 6451, 287379, 12711292, 563046972, 24932875448, 1104148318540, 48896363697435, 2165344586789384, 95890854634053213, 4246463765107286355, 188051863862618823831, 8327753561924846574597, 368789108809170527549222

Offset

1,1

Comments

Column 3 of A204685

Links

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

Formula

Empirical: a(n) = 33*a(n-1) +576*a(n-2) -2576*a(n-3) -38824*a(n-4) +127580*a(n-5) +909748*a(n-6) -3116838*a(n-7) -7687952*a(n-8) +37104276*a(n-9) -63026296*a(n-10) -432695012*a(n-11) +2720629849*a(n-12) -5107909211*a(n-13) +3025539132*a(n-14) +16236494388*a(n-15) -61214998652*a(n-16) +60381991332*a(n-17) +26465066916*a(n-18) -101087636628*a(n-19) +92416374336*a(n-20) +14995740528*a(n-21) -85493406672*a(n-22) +58756380048*a(n-23) +4342368528*a(n-24) -38953846080*a(n-25) +13150955232*a(n-26) +1077909120*a(n-27) -6291032832*a(n-28) +3193509888*a(n-29) +1854296064*a(n-30) for n>33

Example

Some solutions for n=5
..0..1..1....0..0..1....0..0..1....0..0..1....0..0..1....0..0..1....0..0..1
..0..0..1....2..1..2....0..1..0....0..0..1....0..0..1....2..3..1....2..2..1
..2..0..2....2..3..0....2..3..3....1..2..2....1..2..2....1..1..3....0..3..2
..2..1..1....1..3..2....0..1..0....3..2..2....0..1..3....3..3..1....2..0..2
..3..1..0....1..1..2....1..2..1....3..3..1....1..3..3....0..1..1....3..3..1

Crossrefs

Sequence in context: A354285 A210837 A289231 * A205156 A268007 A205305

Adjacent sequences: A204677 A204678 A204679 * A204681 A204682 A204683

Keyword

nonn

Author

R. H. Hardin Jan 18 2012

Status

approved