a(n) = least odd number such that all pairwise sums a(i) + a(j), i < j <= n, are distinct.

Terms

a(0) =1a(1) =3a(2) =5a(3) =9a(4) =15a(5) =25a(6) =41a(7) =59a(8) =77a(9) =105a(10) =147a(11) =189a(12) =255a(13) =303a(14) =363a(15) =423a(16) =515a(17) =631a(18) =747a(19) =825a(20) =951a(21) =1061a(22) =1091a(23) =1215a(24) =1433a(25) =1595a(26) =1723a(27) =1929a(28) =2119a(29) =2321