OFFSET
1,1
EXAMPLE
PROG
(Python)
from sympy import mobius, integer_nthroot
def A075308(n): return int(sum(mobius(x)*(integer_nthroot(10**(n-1), x)[0]-integer_nthroot(10**n, x)[0]) for x in range(2, ((10**(n-1)).bit_length())))-sum(mobius(x)*(integer_nthroot(10**n, x)[0]-1) for x in range((10**(n-1)).bit_length(), (10**n).bit_length()))) if n>2 else n<<2 # Chai Wah Wu, Aug 13 2024
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Zak Seidov, Oct 11 2002
EXTENSIONS
More terms from Jinyuan Wang, Mar 02 2020
STATUS
approved