A249190 Number of length n+6 0..1 arrays with no seven consecutive terms having four times the sum of any three elements equal to three times the sum of the remaining four.

126, 250, 496, 984, 1952, 3872, 7680, 15234, 30218, 59940, 118896, 235840, 467808, 927936, 1840638, 3651058, 7242176, 14365456, 28495072, 56522336, 112116736, 222392834, 441134610, 875027044, 1735688632, 3442882192, 6829242048

Offset: 1

Author

R. H. Hardin, Oct 23 2014

Keywords

• nonn

Comments

Column 1 of A249197.

Examples

			Some solutions for n=6:
..0....0....1....0....1....1....1....0....0....0....0....1....1....0....0....0
..1....1....0....1....1....1....1....0....0....1....1....0....1....1....1....0
..0....0....0....1....1....0....0....1....1....0....1....1....1....0....1....1
..1....0....0....1....0....1....1....0....0....1....1....1....1....0....1....1
..0....1....1....0....0....1....0....1....1....0....1....0....1....1....1....0
..0....1....0....0....1....1....1....0....0....0....0....1....1....0....1....1
..0....1....1....0....1....1....0....1....1....0....0....0....0....0....0....1
..1....1....0....1....0....1....1....1....0....0....0....1....1....0....1....1
..1....0....0....1....1....0....0....1....0....1....1....0....1....0....1....0
..0....0....0....1....0....0....1....0....0....1....1....1....1....0....0....1
..0....1....0....1....1....0....0....1....1....1....1....0....1....1....0....0
..1....0....1....1....1....1....0....1....0....0....0....0....0....0....0....1
		

Links

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

Crossrefs

Cf. A249197.

Formula

Empirical: a(n) = a(n-1) + a(n-2) + a(n-3) + a(n-4) + a(n-5) + a(n-6).

Empirical g.f.: 2*x*(63 + 62*x + 60*x^2 + 56*x^3 + 48*x^4 + 32*x^5) / (1 - x - x^2 - x^3 - x^4 - x^5 - x^6). - Colin Barker, Feb 24 2018