A206164 Number of (n+1) X 4 0..3 arrays with every 2 X 2 subblock in a row having an equal number of equal diagonal or equal antidiagonal elements, adjacent rows differing in this number, and new values 0..3 introduced in row major order.

641, 14182, 463878, 10599630, 345652310, 7934434238, 257597022598, 5939045721006, 191982939898678, 4445181274166302, 143088306500843366, 3326865018494656782, 106651001017976490518, 2489743322080060401278

Offset

1,1

Comments

Column 3 of A206169.

Links

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

Formula

Empirical: a(n) = a(n-1) + 745*a(n-2) - 489*a(n-3) - 5808*a(n-4) + 1584*a(n-5) + 10368*a(n-6) for n>7.

Empirical g.f.: x*(641 + 13541*x - 27849*x^2 - 116389*x^3 + 121496*x^4 + 247632*x^5 - 70272*x^6) / ((1 - x - 4*x^2)*(1 - 741*x^2 - 252*x^3 + 2592*x^4)). - Colin Barker, Jun 13 2018

Example

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

Crossrefs

Cf. A206169.

Sequence in context: A106488 A259997 A256806 * A206378 A229851 A268840

Adjacent sequences: A206161 A206162 A206163 * A206165 A206166 A206167

Keyword

nonn

Author

R. H. Hardin, Feb 04 2012

Status

approved