A268165 Number of n X 2 0..3 arrays with every repeated value in every row and column one larger mod 4 than the previous repeated value, and upper left element zero.

4, 64, 900, 12100, 155236, 1932100, 23444964, 278956804, 3265665316, 37722185284, 430853083236, 4874266035076, 54692207394724, 609340042214596, 6746970728882916, 74302629109627396, 814375880067172900

Offset

1,1

Links

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

Formula

Empirical: a(n) = 23*a(n-1) - 106*a(n-2) - 724*a(n-3) + 4128*a(n-4) + 9216*a(n-5) - 20736*a(n-6).

Empirical g.f.: 4*x*(1 - 7*x - 37*x^2 + 270*x^3 + 540*x^4 - 1296*x^5) / ((1 + 4*x)*(1 - 9*x)*(1 - 12*x + 16*x^2)*(1 - 6*x - 36*x^2)). - Colin Barker, Jan 11 2019

Example

Some solutions for n=5:
..0..3....0..2....0..0....0..0....0..1....0..2....0..0....0..0....0..3....0..2
..0..1....3..2....0..2....3..2....0..2....0..0....2..0....1..2....0..3....2..0
..3..1....3..1....2..3....0..1....3..2....3..1....1..1....1..1....1..0....1..0
..0..2....2..3....0..2....0..2....1..3....1..0....2..1....0..2....3..3....1..3
..1..2....1..1....3..1....3..0....2..0....1..0....1..0....2..2....2..0....0..1

Crossrefs

Column 2 of A268169.

Sequence in context: A264575 A053957 A145244 * A026301 A010042 A154021

Adjacent sequences: A268162 A268163 A268164 * A268166 A268167 A268168

Keyword

nonn

Author

R. H. Hardin, Jan 27 2016

Status

approved