A204947 Number of (n+2)X3 0..2 arrays with every 3X3 subblock having three equal elements in a row horizontally, vertically, diagonally or antidiagonally exactly two different ways, and new values 0..2 introduced in row major order

506, 4041, 33785, 242852, 1834500, 14289768, 108053748, 821739738, 6289319412, 47897599390, 365010473684, 2784935175674, 21230639695872, 161861679826054, 1234296032691188, 9410958469212490, 71754936092737384, 547125231639211406

Offset

1,1

Comments

Column 1 of A204954

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +20*a(n-2) +131*a(n-3) -305*a(n-4) -1790*a(n-5) -2872*a(n-6) +10395*a(n-7) +43528*a(n-8) -6640*a(n-9) -332490*a(n-10) -275912*a(n-11) +1419384*a(n-12) +4752196*a(n-13) +283608*a(n-14) -23930672*a(n-15) -34833608*a(n-16) +29678192*a(n-17) +159431360*a(n-18) +76549344*a(n-19) -463788416*a(n-20) -685792768*a(n-21) +596201344*a(n-22) +2167947008*a(n-23) +1070287872*a(n-24) -2579303936*a(n-25) -3727255552*a(n-26) +349462528*a(n-27) +3207258112*a(n-28) +1212039168*a(n-29) -811302912*a(n-30) -506068992*a(n-31) -42467328*a(n-32)

Example

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

Crossrefs

Sequence in context: A336561 A158633 A204954 * A295992 A122267 A204946

Adjacent sequences: A204944 A204945 A204946 * A204948 A204949 A204950

Keyword

nonn

Author

R. H. Hardin Jan 20 2012

Status

approved