A206312 Number of (n+1)X3 0..3 arrays with the number of clockwise edge increases in every 2X2 subblock equal to two, and every 2X2 determinant nonzero

873, 14990, 258452, 4466450, 77132181, 1332632711, 23019152735, 397663246671, 6869398174303, 118667836512792, 2049943888882611, 35412251178185627, 611735705434058145, 10567560415916348461, 182551476583398721925

Offset

1,1

Comments

Column 2 of A206318

Links

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

Formula

Empirical: a(n) = 7*a(n-1) +178*a(n-2) +165*a(n-3) -2824*a(n-4) -4379*a(n-5) +21326*a(n-6) +27124*a(n-7) -88175*a(n-8) -686*a(n-9) +173432*a(n-10) -238738*a(n-11) -152649*a(n-12) +854730*a(n-13) -1223471*a(n-14) +1084153*a(n-15) -644627*a(n-16) +130265*a(n-17) +200912*a(n-18) -253639*a(n-19) +210358*a(n-20) -155058*a(n-21) +94508*a(n-22) -47283*a(n-23) +17559*a(n-24) -3954*a(n-25) -565*a(n-26) +581*a(n-27) -71*a(n-28) +6*a(n-29)

Example

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

Crossrefs

Sequence in context: A251841 A251085 A334011 * A252211 A045258 A252219

Adjacent sequences: A206309 A206310 A206311 * A206313 A206314 A206315

Keyword

nonn

Author

R. H. Hardin Feb 06 2012

Status

approved