Position of n-th 2 in A031111.

Terms

a(0) =2a(1) =8a(2) =20a(3) =33a(4) =47a(5) =54a(6) =55a(7) =57a(8) =62a(9) =71a(10) =74a(11) =76a(12) =83a(13) =87a(14) =107a(15) =126a(16) =139a(17) =142a(18) =157a(19) =170a(20) =177a(21) =192a(22) =193a(23) =196a(24) =201a(25) =209a(26) =216a(27) =224a(28) =227a(29) =232