Position of n-th 5 in A031100.

Terms

a(0) =3a(1) =20a(2) =38a(3) =41a(4) =43a(5) =45a(6) =47a(7) =49a(8) =56a(9) =74a(10) =100a(11) =127a(12) =147a(13) =150a(14) =153a(15) =154a(16) =156a(17) =181a(18) =208a(19) =235a(20) =262a(21) =267a(22) =270a(23) =273a(24) =276a(25) =279a(26) =289a(27) =316a(28) =343a(29) =370