A210349 1/4 the number of (n+1)X3 0..3 arrays with every 2X2 subblock having one, two or three distinct clockwise edge differences

431, 13566, 423694, 13288986, 416960476, 13085817650, 410707536246, 12890620403588, 404592571598972, 12698808571519484, 398573456240825396, 12509901116822794985, 392644408257072821693, 12323809287572710045051

Offset

1,1

Comments

Column 2 of A210355

Links

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

Formula

Empirical: a(n) = 55*a(n-1) -890*a(n-2) +4374*a(n-3) +14813*a(n-4) -179200*a(n-5) +198626*a(n-6) +1718220*a(n-7) -3858631*a(n-8) -4143905*a(n-9) +14290154*a(n-10) +1274736*a(n-11) -19132266*a(n-12) +4460692*a(n-13) +9184880*a(n-14) -3036040*a(n-15) -1419448*a(n-16) +517280*a(n-17) +1792*a(n-18) -4096*a(n-19) -128*a(n-20)

Example

Some solutions for n=4
..3..1..1....0..1..1....0..3..0....1..1..3....1..2..1....1..1..0....3..0..1
..3..2..1....2..1..2....0..3..3....0..1..1....1..3..2....2..0..0....2..1..2
..1..1..0....2..1..0....1..2..3....0..1..0....1..3..1....0..0..2....3..1..1
..3..2..3....3..2..2....3..2..1....0..1..1....1..3..2....1..1..1....1..3..3
..3..1..0....0..1..3....0..1..1....3..2..0....1..1..2....2..1..0....3..1..3

Crossrefs

Sequence in context: A142802 A003548 A179173 * A048961 A301645 A063463

Adjacent sequences: A210346 A210347 A210348 * A210350 A210351 A210352

Keyword

nonn

Author

R. H. Hardin Mar 20 2012

Status

approved