a(n) = 100*log_10(n) rounded up.

Terms

a(0) =0a(1) =31a(2) =48a(3) =61a(4) =70a(5) =78a(6) =85a(7) =91a(8) =96a(9) =100a(10) =105a(11) =108a(12) =112a(13) =115a(14) =118a(15) =121a(16) =124a(17) =126a(18) =128a(19) =131a(20) =133a(21) =135a(22) =137a(23) =139a(24) =140a(25) =142a(26) =144a(27) =145a(28) =147a(29) =148