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A259085
a(n) = largest k such that the decimal representation of prime(n)^k does not contain the digit 1, or -1 if no such k exists.
2
91, 43, 42, 30, -1, 14, 13, 23, 7, 3, -1, 6, -1, 3, 5, 2, 19, -1, 9, -1, 17, 5, 6, 9, 6, -1, -1, -1, 11, -1, 13, -1, 7, -1, 5, -1, 5, 3, 13, 6, 7, -1, -1, 7, 10, 15, -1, 2, 5, 7, 2, 9, -1, -1, 2, 6, 1, -1, 2, -1, 21, 2, 3, -1, 3, 11, -1, 5, 11, 3, 3, 3, 5, 1
OFFSET
1,1
COMMENTS
These values are only conjectural.
LINKS
Popular Computing (Calabasas, CA), Two Tables, Vol. 1, (No. 9, Dec 1973), page PC9-16.
CROSSREFS
KEYWORD
sign,base
AUTHOR
N. J. A. Sloane, Jun 18 2015
EXTENSIONS
a(14)-a(74) from Hiroaki Yamanouchi, Jun 19 2015
STATUS
approved