A198621 Number of nX2 0..5 arrays with values 0..5 introduced in row major order and each element equal to at least one horizontal or vertical neighbor

1, 3, 14, 76, 488, 3521, 28009, 241590, 2223711, 21519533, 216099699, 2228023793, 23394765858, 248722671553, 2666496996271, 28746778089814, 311062415257234, 3374225209472645, 36661349689794535, 398760168220542400

Offset

1,2

Comments

Column 2 of A198627

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = 26*a(n-1) -225*a(n-2) +616*a(n-3) +987*a(n-4) -5730*a(n-5) -1309*a(n-6) +15122*a(n-7) +15401*a(n-8) -20868*a(n-9) -34559*a(n-10) -3370*a(n-11) +29842*a(n-12) +18864*a(n-13) -3196*a(n-14) -9000*a(n-15) -2600*a(n-16)

Example

Some solutions for n=4
..0..0....0..1....0..0....0..0....0..0....0..1....0..0....0..1....0..0....0..0
..0..0....0..1....0..0....1..1....1..1....0..1....0..0....0..1....1..1....1..2
..1..1....0..0....1..1....1..1....2..0....0..2....0..1....2..2....2..3....1..2
..0..0....1..1....2..2....1..1....2..0....0..2....0..1....1..1....2..3....3..3

Crossrefs

Sequence in context: A364758 A353253 A198702 * A198649 A198656 A240402

Adjacent sequences: A198618 A198619 A198620 * A198622 A198623 A198624

Keyword

nonn

Author

R. H. Hardin Oct 27 2011

Status

approved