Position of n-th 3 in A030298.

Terms

a(0) =8a(1) =10a(2) =14a(3) =16a(4) =18a(5) =21a(6) =26a(7) =31a(8) =33a(9) =37a(10) =43a(11) =46a(12) =50a(13) =55a(14) =57a(15) =61a(16) =67a(17) =70a(18) =72a(19) =76a(20) =80a(21) =84a(22) =88a(23) =92a(24) =99a(25) =102a(26) =107a(27) =110a(28) =113a(29) =117