Number of digits in 5^(n!).

Terms

a(0) =1a(1) =1a(2) =2a(3) =5a(4) =17a(5) =84a(6) =504a(7) =3523a(8) =28183a(9) =253643a(10) =2536423a(11) =27900646a(12) =334807751a(13) =4352500756a(14) =60935010579a(15) =914025158672