%I
%S 5,7,10,14,18,22,26,30,34,38,42,46,50,54,58,62,66,70,74,78,82,86,90,
%T 94,98,102,106,110,114,118,122,126,130,134,138,142,146,150,154,158,
%U 162,166,170,174,178,182,186,190,194,198,202,206,210,214,218,222,226,230,234,238
%N Number of nondecreasing arrangements of n+2 numbers in 0..3 with the last equal to 3 and each after the second equal to the sum of one or two of the preceding three.
%C Column 3 of A190041.
%H R. H. Hardin, <a href="/A190035/b190035.txt">Table of n, a(n) for n = 1..200</a>
%F Empirical: a(n) = 4*n  2 for n>2.
%F Conjectures from _Colin Barker_, May 03 2018: (Start)
%F G.f.: x*(5  3*x + x^2 + x^3) / (1  x)^2.
%F a(n) = 2*a(n1)  a(n2) for n>4.
%F (End)
%e All solutions for n=4:
%e ..1....1....0....3....2....0....1....0....1....1....0....1....1....1
%e ..1....1....3....3....3....1....1....1....2....1....1....2....3....1
%e ..2....1....3....3....3....1....2....1....3....1....1....2....3....1
%e ..2....1....3....3....3....2....3....2....3....2....1....3....3....2
%e ..3....2....3....3....3....2....3....3....3....3....2....3....3....2
%e ..3....3....3....3....3....3....3....3....3....3....3....3....3....3
%Y Cf. A190041.
%K nonn
%O 1,1
%A _R. H. Hardin_, May 04 2011
