

A234966


Least number k with at least one zero such that k^n contains no zero, or 0 if no such number exists.


0



0, 106, 104, 104, 105, 102, 102, 408, 104, 107, 203, 109, 103, 103, 1056, 3703, 4604, 207, 606, 11018, 3069, 20064
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OFFSET

1,2


COMMENTS

a(n) > 5*10^8 or 0 for n = 23 and for 25 < n < 75.
It is known that a(24) = 12801714 and a(25) = 402.
a(n) > 5*10^9 or 0 for n = 23 and for 25 < n <= 200.  Chai Wah Wu, Apr 25 2019


LINKS



EXAMPLE

a(5) = 105 because 105 is the smallest number with a 0 where 105^5 does not have a 0 (105^5 = 12762815625).


PROG

(Python)
def f(x):
for n in range(10**7):
if "0" in str(n):
if "0" not in str(n**x):
return n
for x in range(1, 75):
if f(x) is None:
print(0)
else:
print(f(x))


CROSSREFS



KEYWORD

nonn,base,more,hard


AUTHOR



STATUS

approved



