The n-th prime minus n gives a triangular number.

Terms

a(0) =1a(1) =2a(2) =4a(3) =5a(4) =7a(5) =13a(6) =34a(7) =37a(8) =46a(9) =62a(10) =104a(11) =111a(12) =210a(13) =259a(14) =274a(15) =296a(16) =306a(17) =439a(18) =488a(19) =502a(20) =513a(21) =751a(22) =763a(23) =817a(24) =969a(25) =998a(26) =1132a(27) =1231a(28) =1405a(29) =1586