0-additive sequence: not the sum of any previous pair.

Terms

a(0) =1a(1) =2a(2) =4a(3) =7a(4) =10a(5) =13a(6) =16a(7) =19a(8) =22a(9) =25a(10) =28a(11) =31a(12) =34a(13) =37a(14) =40a(15) =43a(16) =46a(17) =49a(18) =52a(19) =55a(20) =58a(21) =61a(22) =64a(23) =67a(24) =70a(25) =73a(26) =76a(27) =79a(28) =82a(29) =85