Number of digits in n-th term of A001387.

Terms

a(0) =1a(1) =2a(2) =3a(3) =6a(4) =8a(5) =12a(6) =18a(7) =27a(8) =39a(9) =58a(10) =85a(11) =125a(12) =183a(13) =269a(14) =394a(15) =578a(16) =847a(17) =1242a(18) =1820a(19) =2668a(20) =3910a(21) =5731a(22) =8399a(23) =12310a(24) =18041a(25) =26441a(26) =38751a(27) =56793a(28) =83234a(29) =121986