Position of n-th 4 in A030298.

Terms

a(0) =27a(1) =30a(2) =35a(3) =38a(4) =41a(5) =45a(6) =51a(7) =54a(8) =59a(9) =62a(10) =65a(11) =69a(12) =75a(13) =78a(14) =83a(15) =86a(16) =89a(17) =93a(18) =96a(19) =100a(20) =104a(21) =108a(22) =112a(23) =116a(24) =123a(25) =129a(26) =132a(27) =137a(28) =144a(29) =148