A231694 Number of nX2 0..3 arrays with no element less than a strict majority of its horizontal, vertical and antidiagonal neighbors

4, 28, 272, 1998, 13260, 94996, 691229, 4926082, 35082734, 251198534, 1797886622, 12852933731, 91912956748, 657463618650, 4702487810918, 33632995941197, 240557644773042, 1720590474243847, 12306454228470804, 88021459865552231

Offset

1,1

Comments

Column 2 of A231700

Links

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

Formula

Empirical: a(n) = 16*a(n-1) -100*a(n-2) +414*a(n-3) -1560*a(n-4) +4300*a(n-5) -7915*a(n-6) +14336*a(n-7) -26218*a(n-8) +36856*a(n-9) -47376*a(n-10) +63903*a(n-11) -72545*a(n-12) +70297*a(n-13) -69546*a(n-14) +62746*a(n-15) -45905*a(n-16) +31530*a(n-17) -23245*a(n-18) +11184*a(n-19) -5796*a(n-20) +2196*a(n-21) -1296*a(n-22)

Example

Some solutions for n=6
..3..0....2..2....3..3....0..0....1..1....1..0....2..0....2..2....0..3....1..1
..0..0....0..0....0..0....0..3....1..3....0..0....0..0....3..2....0..2....1..3
..2..3....0..3....0..2....0..0....1..2....3..0....1..2....3..2....0..2....2..3
..0..0....3..0....2..3....0..2....1..0....3..0....0..0....0..0....0..0....0..0
..0..0....0..0....3..0....1..2....0..0....1..0....0..0....0..0....0..0....0..1
..2..0....2..1....0..0....1..1....2..1....1..0....0..0....3..2....2..3....3..2

Crossrefs

Sequence in context: A372747 A245060 A191686 * A112915 A129683 A367474

Adjacent sequences: A231691 A231692 A231693 * A231695 A231696 A231697

Keyword

nonn

Author

R. H. Hardin, Nov 12 2013

Status

approved