Position of n-th 4 in A031067.

Terms

a(0) =11a(1) =29a(2) =58a(3) =60a(4) =71a(5) =72a(6) =77a(7) =95a(8) =102a(9) =125a(10) =131a(11) =134a(12) =142a(13) =144a(14) =147a(15) =162a(16) =185a(17) =222a(18) =224a(19) =251a(20) =267a(21) =269a(22) =272a(23) =285a(24) =288a(25) =289a(26) =296a(27) =299a(28) =301a(29) =311