Position of n-th 6 in A031111.

Terms

a(0) =12a(1) =32a(2) =35a(3) =42a(4) =49a(5) =51a(6) =56a(7) =80a(8) =95a(9) =111a(10) =119a(11) =121a(12) =123a(13) =130a(14) =141a(15) =173a(16) =185a(17) =195a(18) =208a(19) =220a(20) =223a(21) =229a(22) =235a(23) =245a(24) =257a(25) =268a(26) =271a(27) =311a(28) =323a(29) =324