Position of n-th 2 in A030413.

Terms

a(0) =2a(1) =6a(2) =13a(3) =15a(4) =21a(5) =23a(6) =28a(7) =29a(8) =34a(9) =36a(10) =38a(11) =40a(12) =44a(13) =47a(14) =52a(15) =53a(16) =56a(17) =66a(18) =67a(19) =69a(20) =72a(21) =73a(22) =74a(23) =78a(24) =84a(25) =88a(26) =95a(27) =100a(28) =105a(29) =115