

A131551


Least power of 3 having exactly n consecutive 2's in its decimal representation.


9



3, 19, 148, 253, 330, 2380, 2124, 30598, 22791, 238582, 107187, 1521134, 10363119, 9995030, 68353787
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OFFSET

1,1


LINKS

Table of n, a(n) for n=1..15.


EXAMPLE

a(3)=148 because 3^148(i.e. 41109831670569663658300086939077404909608122265524774868353822811305361) is the smallest power of 3 to contain a run of 3 consecutive twos in its decimal form.


MATHEMATICA

a = ""; Do[ a = StringJoin[a, "2"]; b = StringJoin[a, "2"]; k = 1; While[ StringPosition[ ToString[3^k], a] == {}  StringPosition[ ToString[3^k], b] != {}, k++ ]; Print[k], {n, 1, 10} ]


CROSSREFS

Cf. A195269, A131552, A131550, A131549, A131548, A131547, A131546, A131545, A131544.
Sequence in context: A080833 A073516 A005258 * A074546 A054316 A006289
Adjacent sequences: A131548 A131549 A131550 * A131552 A131553 A131554


KEYWORD

more,nonn,base


AUTHOR

Shyam Sunder Gupta, Aug 26 2007


EXTENSIONS

a(11)a(14) from Lars Blomberg, Feb 02 2013
a(15) from Bert Dobbelaere, Mar 04 2019


STATUS

approved



