a(n) = ceiling(10*log(n)).

Terms

a(0) =0a(1) =7a(2) =11a(3) =14a(4) =17a(5) =18a(6) =20a(7) =21a(8) =22a(9) =24a(10) =24a(11) =25a(12) =26a(13) =27a(14) =28a(15) =28a(16) =29a(17) =29a(18) =30a(19) =30a(20) =31a(21) =31a(22) =32a(23) =32a(24) =33a(25) =33a(26) =33a(27) =34a(28) =34a(29) =35