a(n) = floor(1000*log_2(n)).

Terms

a(0) =0a(1) =1000a(2) =1584a(3) =2000a(4) =2321a(5) =2584a(6) =2807a(7) =3000a(8) =3169a(9) =3321a(10) =3459a(11) =3584a(12) =3700a(13) =3807a(14) =3906a(15) =4000a(16) =4087a(17) =4169a(18) =4247a(19) =4321a(20) =4392a(21) =4459a(22) =4523a(23) =4584a(24) =4643a(25) =4700a(26) =4754a(27) =4807a(28) =4857a(29) =4906