Position of n-th 5 in A031027.

Terms

a(0) =4a(1) =17a(2) =18a(3) =23a(4) =30a(5) =44a(6) =47a(7) =52a(8) =53a(9) =60a(10) =71a(11) =74a(12) =82a(13) =95a(14) =98a(15) =118a(16) =134a(17) =142a(18) =168a(19) =179a(20) =181a(21) =187a(22) =192a(23) =201a(24) =203a(25) =204a(26) =211a(27) =214a(28) =231a(29) =239