a(n) = least value such that sequence increases and pairwise differences are unique.

Terms

a(0) =1a(1) =4a(2) =5a(3) =10a(4) =12a(5) =22a(6) =35a(7) =49a(8) =64a(9) =84a(10) =100a(11) =122a(12) =141a(13) =169a(14) =225a(15) =271a(16) =295a(17) =338a(18) =399a(19) =465a(20) =547a(21) =579a(22) =670a(23) =745a(24) =816a(25) =917a(26) =993a(27) =1033a(28) =1172a(29) =1258