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A109135
Least number whose n-th power is exclusionary (or 0 if no such n exists). An exclusionary n-th power m^n is one made up of digits not appearing in m, which itself consists of distinct digits.
1
0, 2, 2, 2, 0, 2, 3, 3, 0, 3, 3, 2, 0, 2, 0, 2, 0, 0, 3, 2, 0, 2, 2, 7, 0, 2, 3, 3, 0, 0, 0, 0, 0, 2, 2, 2, 0, 0, 2, 3, 0, 2, 0, 0, 0, 2, 0, 0, 0, 3, 0, 0, 0, 2, 3, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
OFFSET
2,2
COMMENTS
a(n)=0 for n=1(mod 4)=A016813.
a(4k+1) = 0. All other zeros are unproved and have been checked up to m = 1000. - David Wasserman, May 27 2008
REFERENCES
H. Ibstedt, Solution to Problem 2623, "Exclusionary Powers", pp. 346-9 Journal of Recreational Mathematics, Vol. 32 No.4 2003-4 Baywood NY.
CROSSREFS
Cf. A113951.
Sequence in context: A216265 A336694 A130277 * A264136 A274850 A349437
KEYWORD
less,nonn,base
AUTHOR
Lekraj Beedassy, Aug 17 2005
EXTENSIONS
More terms from David Wasserman, May 27 2008
STATUS
approved