%I #14 Jan 09 2019 16:11:12
%S 3,6,22,105,566,3256,19489,119713,748342,4735446,30229772,194242153,
%T 1254381857,8132826045,52900345681,345022543105,2255449994038,
%U 14773402692946,96935423713906,637019314585501
%N a(n) = 1 + C(2*n,n) + C(3*n,n).
%H Seiichi Manyama, <a href="/A029848/b029848.txt">Table of n, a(n) for n = 0..1000</a>
%p a:=n->1+binomial(2*n,n)+binomial(3*n,n): seq(a(n),n=0..20); # _Muniru A Asiru_, Aug 12 2018
%t Table[1+Binomial[2n,n]+Binomial[3n,n],{n,0,30}] (* _Harvey P. Dale_, Jan 09 2019 *)
%o (PARI) a(n) = 1 + binomial(2*n, n) + binomial(3*n, n); \\ _Michel Marcus_, Aug 12 2018
%o (GAP) List([0..20],n->1+Binomial(2*n,n)+Binomial(3*n,n)); # _Muniru A Asiru_, Aug 12 2018
%Y Cf. A000984, A096131.
%K nonn
%O 0,1
%A _N. J. A. Sloane_