Smallest number for which Knuth's power tree method produces an addition chain of length n.

Terms

a(0) =1a(1) =2a(2) =3a(3) =5a(4) =7a(5) =11a(6) =19a(7) =29a(8) =47a(9) =71a(10) =127a(11) =191a(12) =319a(13) =551a(14) =1007a(15) =1711a(16) =2687a(17) =4703a(18) =8447a(19) =15179a(20) =28079a(21) =45997a(22) =89599a(23) =138959a(24) =257513a(25) =485657a(26) =834557a(27) =1433501a(28) =2854189a(29) =4726127