A222337 Number of n X 4 0..6 arrays with no entry increasing mod 7 by 6 rightwards or downwards, starting with upper left zero.

216, 178746, 147918906, 122408393436, 101297497221786, 83827445649884946, 69370328359709445996, 57406526220963704077986, 47506035082750189614687546, 39313010520733216994188515036, 32532978041867113135439462852106

Offset: 1

Author

R. H. Hardin, Feb 15 2013

Keywords

• nonn

Comments

Column 4 of A222340.

Examples

			Some solutions for n=3:
..0..0..2..0....0..2..2..0....0..2..0..0....0..2..0..0....0..2..2..0
..0..3..5..0....0..3..3..0....0..5..3..0....0..0..2..0....0..3..4..0
..0..3..1..1....2..3..3..5....3..3..4..4....3..5..6..3....0..3..0..1
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..109

Crossrefs

Cf. A222340.

Formula

Empirical: a(n) = 873*a(n-1) - 38091*a(n-2) + 387974*a(n-3).

Empirical g.f.: 6*x*(36 - 1637*x + 16884*x^2) / (1 - 873*x + 38091*x^2 - 387974*x^3). - Colin Barker, Mar 15 2018