Actually, 1414 18 bytes
A simple algorithm.
Edit: Fixing a bug for n == 1
;;¬╤$@u*'1@+╪i ;;D╤$0D@H@u*'1@+╪i Ungolfing
Implicit input: n ;; Duplicate n twice. ¬╤$D╤$ Push str(10**(n-21)) @u0D@H Push n+1str(10**(n-1))[:-1] * @u* Push str(10**(n-2)) * (n+1) '1@+ Append a "1" ╪ Split into chunks of length n i Flatten this list onto the stack Implicit print