A184379 1/12 the number of (n+2)X4 0..2 arrays with each 3X3 subblock containing three of each value

545, 1494, 4281, 13616, 55386, 242370, 1165496, 6248040, 34487190, 195981866, 1145052186, 6737361360, 39912443060, 237978427224, 1421256784506, 8501521627826, 50931916877226, 305246808679080, 1830112280897396

Offset

1,1

Comments

Column 2 of A184386

Links

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

Formula

Empirical: a(n)=12*a(n-1)-47*a(n-2)+184*a(n-3)-1380*a(n-4)+5264*a(n-5)-12447*a(n-6)+56628*a(n-7)-206001*a(n-8)+396180*a(n-9)-1125036*a(n-10)+3788388*a(n-11)-6578172*a(n-12)+12197952*a(n-13)-36410148*a(n-14)+59740416*a(n-15)-75446640*a(n-16)+186268896*a(n-17)-295472448*a(n-18)+264166272*a(n-19)-475844544*a(n-20)+739031040*a(n-21)-485409024*a(n-22)+473651712*a(n-23)-725594112*a(n-24)+362797056*a(n-25)

Example

Some solutions with a(1,1)=0 for 6X4
..0..1..2..0....0..0..2..1....0..0..1..0....0..1..0..0....0..1..2..0
..0..0..1..0....1..0..1..0....2..2..1..2....2..1..2..2....2..0..1..2
..2..2..1..2....1..2..2..1....0..1..2..0....1..2..0..1....0..2..1..0
..2..1..0..2....0..0..2..1....0..1..0..0....0..1..0..0....1..0..2..1
..0..1..0..0....1..0..1..0....2..1..2..2....2..1..2..2....1..0..2..1
..1..2..2..1....2..1..2..2....2..1..0..2....2..1..0..2....2..0..1..2

Crossrefs

Sequence in context: A264948 A159626 A020259 * A353023 A053327 A252537

Adjacent sequences: A184376 A184377 A184378 * A184380 A184381 A184382

Keyword

nonn

Author

R. H. Hardin Jan 12 2011

Status

approved