Position of n-th 2 in A031057.

Terms

a(0) =13a(1) =15a(2) =17a(3) =19a(4) =86a(5) =89a(6) =92a(7) =95a(8) =157a(9) =160a(10) =163a(11) =166a(12) =169a(13) =172a(14) =175a(15) =178a(16) =181a(17) =182a(18) =184a(19) =185a(20) =187a(21) =188a(22) =190a(23) =191a(24) =193a(25) =196a(26) =199a(27) =202a(28) =205a(29) =208