Position of n-th 4 in A007376.

Terms

a(0) =4a(1) =19a(2) =39a(3) =59a(4) =70a(5) =72a(6) =74a(7) =76a(8) =78a(9) =79a(10) =80a(11) =82a(12) =84a(13) =86a(14) =88a(15) =99a(16) =119a(17) =139a(18) =159a(19) =179a(20) =204a(21) =234a(22) =264a(23) =294a(24) =311a(25) =314a(26) =317a(27) =320a(28) =323a(29) =324