a(0) = 1, a(1) = 1 and for n >= 2, a(n) = floor(4 * a(n-2) * a(n-1) / (a(n-2) + a(n-1))).

Terms

a(0) =1a(1) =1a(2) =2a(3) =2a(4) =4a(5) =5a(6) =8a(7) =12a(8) =19a(9) =29a(10) =45a(11) =70a(12) =109a(13) =170a(14) =265a(15) =414a(16) =646a(17) =1009a(18) =1575a(19) =2460a(20) =3840a(21) =5997a(22) =9364a(23) =14622a(24) =22833a(25) =35654a(26) =55676a(27) =86940a(28) =135762a(29) =211998