%I #8 Jan 30 2016 02:31:19
%S 0,2,3,0,5,6,2,6,7,3,7,8,4,8,9,5,9,10,6,10,11,7,11,12,8,12,13,9,13,14,
%T 10,14,15,11,15,16,12,16,17,13,17,18,14,18,19,15,19,20,16,20,21,17,21,
%U 22,18,22,23,19,23,24,20,24,25,21,25,26,22,26,27,23
%N Column 3 of the square array in A267181.
%F Conjectures from _Colin Barker_, Jan 30 2016: (Start)
%F a(n) = a(n-1)+a(n-3)-a(n-4) for n>4.
%F G.f.: x*(2+x-3*x^2+3*x^3-x^5-x^6) / ((1-x)^2*(1+x+x^2)).
%F (End)
%Y Cf. A267181.
%K nonn
%O 0,2
%A _N. J. A. Sloane_, Jan 17 2016