%I #3 Mar 30 2012 18:56:00
%S 2,4,11,28,68,169,470,1276,3395,9016,26240,74017,204590,568120,
%T 1659350,4770820,13538480,38435515,113673998,331360936,955040204,
%U 2757123412,8185543376,24071728150,70215321944,204746123776,612178795262,1813222985320
%N a(n) = s(n+3)/3, where s is A024961.
%K nonn
%O 1,1
%A _Clark Kimberling_