Number of Carmichael numbers (A002997) less than 10^n.

Terms

a(0) =0a(1) =0a(2) =1a(3) =7a(4) =16a(5) =43a(6) =105a(7) =255a(8) =646a(9) =1547a(10) =3605a(11) =8241a(12) =19279a(13) =44706a(14) =105212a(15) =246683a(16) =585355a(17) =1401644a(18) =3381806a(19) =8220777a(20) =20138200a(21) =49679870a(22) =123381982a(23) =308279939