A236658 Number of (n+1)X(1+1) 0..2 arrays colored with the maximum plus the upper median plus the lower median of every 2X2 subblock

81, 518, 3300, 21372, 138364, 891832, 5750552, 37123784, 239612080, 1546031840, 9976218688, 64380915200, 415463316768, 2680986516336, 17300668796832, 111644039268528, 720453032600368, 4649158495388496, 30001572938739392

Offset

1,1

Comments

Column 1 of A236663

Links

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

Formula

Empirical: a(n) = 86*a(n-3) +693*a(n-4) +2090*a(n-5) +6696*a(n-6) +7704*a(n-7) -24436*a(n-8) -96408*a(n-9) -299268*a(n-10) -335040*a(n-11) +729732*a(n-12) +2128728*a(n-13) +3765488*a(n-14) +1789376*a(n-15) -13301760*a(n-16) -16992768*a(n-17) +7848704*a(n-18) +15690752*a(n-19) +10651648*a(n-20) +9836544*a(n-21) -9748480*a(n-22) -12713984*a(n-23)

Example

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

Crossrefs

Sequence in context: A253314 A253662 A253731 * A236641 A253307 A235784

Adjacent sequences: A236655 A236656 A236657 * A236659 A236660 A236661

Keyword

nonn

Author

R. H. Hardin, Jan 29 2014

Status

approved