a(n) = 10000*log_10(n) rounded down.

Terms

a(0) =0a(1) =3010a(2) =4771a(3) =6020a(4) =6989a(5) =7781a(6) =8450a(7) =9030a(8) =9542a(9) =10000a(10) =10413a(11) =10791a(12) =11139a(13) =11461a(14) =11760a(15) =12041a(16) =12304a(17) =12552a(18) =12787a(19) =13010a(20) =13222a(21) =13424a(22) =13617a(23) =13802a(24) =13979a(25) =14149a(26) =14313a(27) =14471a(28) =14623