A180727 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

A180727

Smallest power of 21 that begins with n.

1, 21, 37822859361, 441, 5842587018385982521381124421, 68122318582951682301, 794280046581, 85766121, 9261, 10523016528610349434285830688358359761, 1136272165922724266740722458520501, 122694327386105632949003612841

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Table of n, a(n) for n=1..12.

MATHEMATICA

With[{s=21^Range[0, 100]}, Table[SelectFirst[s, Take[IntegerDigits[ #], IntegerLength[ n]] == IntegerDigits[ n]&], {n, 30}]]//Quiet (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Mar 24 2020 *)

CROSSREFS

Cf. A180725, A180728, A180729

Sequence in context: A138080 A013814 A013898 * A250487 A062012 A104786

Adjacent sequences: A180724 A180725 A180726 * A180728 A180729 A180730

KEYWORD

base,nonn

AUTHOR

Daniel Mondot (dmondot(AT)gmail.com), Sep 18 2010

STATUS

approved