%I #9 Dec 08 2020 02:31:31
%S 0,0,4,11,24,52,110,228,467,949,1916,3848,7696,15342,30505,60527,
%T 119892,237156,468590,925032,1824727,3597289,7088216,13961168,
%U 27489168,54110618,106489245,209531251,412217072,810865812,1594878078,3136673996,6168522827,12130206941
%N a(n) = A333650(n, 3) for n >= 3; a(1) = a(2) = 0.
%Y Cf. A333650, A339494.
%K nonn
%O 1,3
%A _Peter Luschny_, Dec 07 2020