OFFSET
0,2
LINKS
Chai Wah Wu, Table of n, a(n) for n = 0..1000
FORMULA
a(n) = round(10^(n/5)). - Wesley Ivan Hurt, Jun 23 2015
MAPLE
MATHEMATICA
Round[(10^(Range[0, 50]/5))] (* Paolo Xausa, Jul 02 2024 *)
PROG
(Python)
from gmpy2 import iroot_rem
def A018142(n):
i, j = iroot_rem(10**n, 5)
return int(i) + int(32*j >= 10*i*(4*i*(2*i*(i + 1) + 1) + 1) + 1) # Chai Wah Wu, Aug 18 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved