OFFSET
2,1
COMMENTS
It is very probable that a(n) = 2 for n > 87.
EXAMPLE
7 is the smallest number with nonzero digits such that 7^4 has at least one zero, so a(4) = 7.
MATHEMATICA
m[n_] := Min@ IntegerDigits@n; a[1]=0; a[n_] := Block[{k=2}, While[m[k] == 0 || m[k^n] > 0, k++]; k]; Array[a, 70] (* Giovanni Resta, Jan 11 2014 *)
PROG
(Python)
def f(x):
..for n in range(10**7):
....if str(n).find("0") == -1:
......if str(n**x).find("0") > -1:
........return n
x = 1
while x < 75:
..if f(x) == None:
....print(0)
..else:
....print(f(x))
..x += 1
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Derek Orr, Jan 02 2014
STATUS
approved