a(0) = 1, then twice the Fibonacci sequence.

Terms

a(0) =1a(1) =2a(2) =2a(3) =4a(4) =6a(5) =10a(6) =16a(7) =26a(8) =42a(9) =68a(10) =110a(11) =178a(12) =288a(13) =466a(14) =754a(15) =1220a(16) =1974a(17) =3194a(18) =5168a(19) =8362a(20) =13530a(21) =21892a(22) =35422a(23) =57314a(24) =92736a(25) =150050a(26) =242786a(27) =392836a(28) =635622a(29) =1028458