A242237 Number of length n+6+1 0..6 arrays with every value 0..6 appearing at least once in every consecutive 6+2 elements, and new values 0..6 introduced in order.

28, 70, 148, 298, 592, 1174, 2332, 4642, 9256, 18442, 36736, 73174, 145756, 290338, 578344, 1152046, 2294836, 4571230, 9105724, 18138274, 36130792, 71971246, 143364148, 285576250, 568857664, 1133144098, 2257182472, 4496226670

Offset: 1

Author

R. H. Hardin, May 08 2014

Keywords

• nonn

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..117

Crossrefs

Column 6 of A242239.

Formula

Empirical: a(n) = a(n-1) + a(n-2) + a(n-3) + a(n-4) + a(n-5) + a(n-6) + a(n-7).

Empirical g.f.: 2*x*(14 + 21*x + 25*x^2 + 26*x^3 + 24*x^4 + 19*x^5 + 11*x^6) / (1 - x - x^2 - x^3 - x^4 - x^5 - x^6 - x^7). - Colin Barker, Nov 01 2018