A242237 - OEIS

%I #10 Nov 01 2018 06:29:05

%S 28,70,148,298,592,1174,2332,4642,9256,18442,36736,73174,145756,

%T 290338,578344,1152046,2294836,4571230,9105724,18138274,36130792,

%U 71971246,143364148,285576250,568857664,1133144098,2257182472,4496226670

%N 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.

%H R. H. Hardin, <a href="/A242237/b242237.txt">Table of n, a(n) for n = 1..117</a>

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

%F 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

%e Some solutions for n=5:

%e ..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0

%e ..1....1....1....1....1....1....1....1....1....1....1....1....1....0....1....1

%e ..2....2....2....2....2....2....2....2....2....2....2....2....2....1....2....2

%e ..3....3....0....3....3....3....0....3....3....3....3....3....3....2....3....3

%e ..4....4....3....4....4....0....3....4....4....4....4....4....1....3....4....4

%e ..0....1....4....5....0....4....4....5....0....5....5....5....4....4....5....5

%e ..5....5....5....1....5....5....5....6....5....6....0....3....5....5....6....1

%e ..6....6....6....6....6....6....6....0....6....0....6....6....6....6....1....6

%e ..1....0....1....0....1....1....1....3....2....5....1....0....0....1....0....0

%e ..3....2....0....3....2....2....0....1....1....1....2....1....5....0....2....2

%e ..2....3....2....2....3....3....2....2....3....2....3....2....2....2....3....3

%e ..3....4....4....3....0....1....5....6....5....3....5....3....3....1....4....6

%Y Column 6 of A242239.

%K nonn

%O 1,1

%A _R. H. Hardin_, May 08 2014