A235851 Number of (n+1) X (2+1) 0..3 arrays with the upper median equal to the lower median in every 2 X 2 subblock.

688, 9600, 121244, 1629216, 21301696, 283036828, 3731137160, 49409402632, 652743993308, 8635064547136, 114147434529696, 1509558147820252, 19958656976746504, 263919164460103464, 3489616685959821692

Offset

1,1

Comments

Column 2 of A235856.

Links

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

Formula

Empirical: a(n) = 15*a(n-1) +63*a(n-2) -1386*a(n-3) +1099*a(n-4) +35227*a(n-5) -85405*a(n-6) -221384*a(n-7) +716768*a(n-8) +332972*a(n-9) -1748080*a(n-10) +329248*a(n-11) +1044480*a(n-12) -421888*a(n-13).

Example

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

Crossrefs

Cf. A235856.

Sequence in context: A252642 A252084 A211162 * A057116 A025355 A025347

Adjacent sequences: A235848 A235849 A235850 * A235852 A235853 A235854

Keyword

nonn

Author

R. H. Hardin, Jan 16 2014

Status

approved