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A176767 Smallest power of 7 whose decimal expansion contains n. 1
2401, 1, 2401, 343, 49, 823543, 16807, 7, 16807, 49, 96889010407, 117649, 13841287201, 13841287201, 11398895185373143, 4747561509943, 16807, 117649, 11398895185373143, 1977326743, 13841287201, 3909821048582988049 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,1
COMMENTS
This is to 7 as A176763 is to 3 and as A030001 is to 2.
LINKS
FORMULA
a(n) = MIN{A000420(i) such that n in decimal representation is a substring of A000420(i)}.
a(n) = 7^A062524(n). - Michel Marcus, Sep 30 2014
EXAMPLE
a(1) = 1 because 7^0 = 1 has "1" as a substring (not a proper substring, though).
a(2) = 2401 because 7^4 = 2401 has "2" as a substring.
a(3) = 343 because 7^3 = 343 has "3" as a substring.
CROSSREFS
Sequence in context: A235259 A321638 A005073 * A018865 A186488 A186487
KEYWORD
base,easy,nonn
AUTHOR
Jonathan Vos Post, Apr 25 2010
EXTENSIONS
More terms from Sean A. Irvine and Jon E. Schoenfield, May 05 2010
Extended to a(0) by M. F. Hasler, Oct 03 2014
STATUS
approved

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Last modified February 27 14:28 EST 2024. Contains 370376 sequences. (Running on oeis4.)