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

1,1

Comments

Column 1 of A249197.

Links

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

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

Example

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

Crossrefs

Cf. A249197.

Sequence in context: A254370 A325932 A109024 * A356143 A254465 A063334

Adjacent sequences: A249187 A249188 A249189 * A249191 A249192 A249193

Keyword

nonn

Author

R. H. Hardin, Oct 23 2014

Status

approved