A176769 Smallest power of 9 whose decimal expansion contains n.

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.

Links

Paolo Xausa, Table of n, a(n) for n = 0..10000

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

Cf. A001018, A030001, A176763, A176764-A176773.

Sequence in context: A359310 A321826 A176763 * A255893 A046323 A368950

Adjacent sequences: A176766 A176767 A176768 * A176770 A176771 A176772

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