Floor-Sqrt transform of the binomial coefficients binomial(3*n,n) (A005809).

Terms

a(0) =1a(1) =1a(2) =3a(3) =9a(4) =22a(5) =54a(6) =136a(7) =340a(8) =857a(9) =2164a(10) =5481a(11) =13911a(12) =35379a(13) =90124a(14) =229913a(15) =587254a(16) =1501615a(17) =3843314a(18) =9845118a(19) =25238541a(20) =64744455a(21) =166190960a(22) =426829202a(23) =1096784835a(24) =2819620836a(25) =7251796132a(26) =18658280277a(27) =48023738374a(28) =123648031266a(29) =318460151301