%I #4 Oct 08 2014 04:02:01
%S 2,15,52,125,306,555,992,1673,2606,3663,5024,6777,8914,11379,14264,
%T 17729,21738,26191,31204,36933,43322,50243,57892,66645,76034,86163,
%U 97156,109293,122350,136083,150744,166801,183978,202119,221164,241881,263758
%N Number of length 3+3 0..n arrays with every four consecutive terms having the sum of some three elements equal to three times the fourth
%C Row 3 of A248537
%H R. H. Hardin, <a href="/A248540/b248540.txt">Table of n, a(n) for n = 1..210</a>
%e Some solutions for n=6
%e ..6....0....5....4....3....2....0....4....3....5....5....6....0....0....1....2
%e ..1....1....5....5....1....2....5....2....0....4....3....0....2....5....6....3
%e ..5....1....4....3....3....3....1....3....2....5....6....3....5....2....2....0
%e ..4....2....2....4....5....1....2....3....3....6....6....3....1....1....3....3
%e ..6....0....5....4....3....6....0....4....3....5....5....6....0....0....1....2
%e ..5....1....5....5....1....2....1....2....0....4....3....0....2....1....6....3
%K nonn
%O 1,1
%A _R. H. Hardin_, Oct 08 2014