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A176769
Smallest power of 9 whose decimal expansion contains n.
1
59049, 1, 729, 531441, 59049, 6561, 6561, 729, 81, 9, 31381059609, 205891132094649, 150094635296999121, 31381059609, 531441, 150094635296999121, 16677181699666569, 1350851717672992089, 2541865828329, 8862938119652501095929
OFFSET
0,1
COMMENTS
This is to 9 as A176763 is to 3 and as A030001 is to 2.
FORMULA
a(n) = MIN{A001019(i) such that n in decimal representation is a substring of A001019(i)}.
a(n) = 9^A062526(n). - Michel Marcus, Sep 30 2014
EXAMPLE
a(1) = 1 because 9^0 = 1 has "1" as a substring (not a proper substring, though).
a(2) = 729 because 9^3 = 729 has "2" as a substring.
a(3) = 531441 because 9^6 = 531441 has "3" as a substring.
MATHEMATICA
A176769[n_] := Block[{k = -1}, While[StringFreeQ[IntegerString[9^++k], IntegerString[n]]]; 9^k]; Array[A176769, 50, 0] (* Paolo Xausa, Apr 04 2024 *)
CROSSREFS
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
a(0) prepended by Paolo Xausa, Apr 04 2024
STATUS
approved