a(0) = 0, a(1) = 1 and for n >= 2, a(n) = floor(2 * sqrt(a(n-2) * a(n-1))).

Terms

a(0) =0a(1) =1a(2) =1a(3) =2a(4) =2a(5) =4a(6) =5a(7) =8a(8) =12a(9) =19a(10) =30a(11) =47a(12) =75a(13) =118a(14) =188a(15) =297a(16) =472a(17) =748a(18) =1188a(19) =1885a(20) =2992a(21) =4749a(22) =7538a(23) =11966a(24) =18994a(25) =30151a(26) =47861a(27) =75975a(28) =120602a(29) =191444