OFFSET
2,1
FORMULA
a(n) = 0 for any n > 9876543210. - Rémy Sigrist, Jul 06 2019
EXAMPLE
For n = 2, 2^29 = 536870912, which is the largest power of 2 to contain distinct digits.
MATHEMATICA
a[n_] := SelectFirst[ Range[ Floor@ Log[n, 10^10], 0, -1], (Sort[#] == Union[#]) &@ IntegerDigits[ n^#] &]; Array[a, 86, 2] (* Giovanni Resta, Jul 07 2019 *)
PROG
(Python)
def distinct_digits(n):
p = math.floor(math.log(10**10)/math.log(n))
while p >= 1:
d = n**p
if len(set(str(d))) == len(str(d)):
return(p)
else:
p = p - 1
return(0)
(PARI) a(n) = forstep (k=logint(10^10, n), 0, -1, my (d=digits(n^k)); if (#d==#Set(d), return (k))) \\ Rémy Sigrist, Jul 06 2019
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Tom Bryan, Jul 05 2019
EXTENSIONS
More terms from Rémy Sigrist, Jul 06 2019
STATUS
approved