%I #5 Feb 01 2016 10:20:46
%S 2,4,11,33,114,435,1829,8377,41504,220958,1256927,7602273,48676925,
%T 328685063,2332565079,17344752142,134774766541,1091701884974,
%U 9198355199792,80459135884925,729337831748484,6840215461149149
%N Number of length-(n+1) 0..n arrays with new values introduced in sequential order, and with new repeated values introduced in sequential order, both starting with zero.
%C Diagonal of A268327.
%H R. H. Hardin, <a href="/A268320/b268320.txt">Table of n, a(n) for n = 1..147</a>
%e Some solutions for n=9
%e ..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
%e ..1....0....0....1....1....1....0....1....1....1....1....0....1....1....1....1
%e ..2....0....1....0....2....2....1....2....2....2....2....0....2....2....2....2
%e ..3....1....2....2....0....3....2....3....1....3....3....0....3....1....3....3
%e ..4....2....1....0....0....2....1....0....3....4....4....1....4....3....4....2
%e ..0....1....2....3....3....4....2....4....1....5....2....0....1....4....5....3
%e ..1....3....3....4....4....3....1....0....0....6....5....2....2....0....6....2
%e ..5....1....2....3....5....4....1....4....0....1....3....1....0....4....0....4
%e ..2....2....0....2....3....3....2....5....3....6....6....3....5....1....4....5
%e ..3....4....2....5....6....4....1....4....1....7....5....0....3....0....7....6
%Y Cf. A268327.
%K nonn
%O 1,1
%A _R. H. Hardin_, Feb 01 2016