A180727 Smallest power of 21 that begins with n.

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

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