a(n) is the smallest k > n such that n^(k-n) == 1 (mod k).

Terms

a(0) =2a(1) =20737a(2) =9299a(3) =7a(4) =13a(5) =311a(6) =15a(7) =127a(8) =17a(9) =37a(10) =14a(11) =23a(12) =17a(13) =157a(14) =106a(15) =31a(16) =29a(17) =312953a(18) =45a(19) =95951a(20) =41a(21) =91a(22) =33a(23) =47a(24) =28a(25) =95a(26) =35a(27) =271a(28) =35a(29) =9629