A232346 Number of (n+1)X(2+1) 0..2 arrays with every element both >= and <= some horizontal, vertical, diagonal or antidiagonal neighbor

207, 5309, 111607, 2435979, 53921761, 1191667231, 26307585827, 580823169565, 12824535830819, 283163762696631, 6252174866776925, 138046249324516211, 3048023392164446735, 67299522236516456501, 1485954983763378383467

Offset

1,1

Comments

Column 2 of A232352

Links

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

Formula

Empirical: a(n) = 18*a(n-1) +50*a(n-2) +715*a(n-3) +3508*a(n-4) +5186*a(n-5) +5127*a(n-6) -9378*a(n-7) -73758*a(n-8) -108752*a(n-9) -97333*a(n-10) -110585*a(n-11) -18852*a(n-12) +50833*a(n-13) +28853*a(n-14) +12012*a(n-15) +71*a(n-16) -10643*a(n-17) -5897*a(n-18) -4501*a(n-19) -989*a(n-20) +28*a(n-21) +100*a(n-22) +56*a(n-23)

Example

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

Crossrefs

Sequence in context: A205194 A204868 A223650 * A052093 A103477 A080531

Adjacent sequences: A232343 A232344 A232345 * A232347 A232348 A232349

Keyword

nonn

Author

R. H. Hardin, Nov 22 2013

Status

approved