Position of n-th 5 in A031111.

Terms

a(0) =4a(1) =24a(2) =41a(3) =43a(4) =44a(5) =58a(6) =67a(7) =88a(8) =92a(9) =99a(10) =101a(11) =112a(12) =122a(13) =131a(14) =148a(15) =149a(16) =152a(17) =158a(18) =164a(19) =175a(20) =180a(21) =184a(22) =188a(23) =189a(24) =207a(25) =211a(26) =213a(27) =217a(28) =236a(29) =252