Largest number whose 5th power has n digits.

Terms

a(0) =1a(1) =2a(2) =3a(3) =6a(4) =9a(5) =15a(6) =25a(7) =39a(8) =63a(9) =99a(10) =158a(11) =251a(12) =398a(13) =630a(14) =999a(15) =1584a(16) =2511a(17) =3981a(18) =6309a(19) =9999a(20) =15848a(21) =25118a(22) =39810a(23) =63095a(24) =99999a(25) =158489a(26) =251188a(27) =398107a(28) =630957a(29) =999999