

A131625


Numbers k such that decimal expansion of 3^k contains no 2.


2



0, 1, 2, 4, 8, 9, 10, 11, 12, 15, 20, 22, 29, 34, 35, 54, 59
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OFFSET

1,3


COMMENTS

I conjecture that 59 is the last term.


LINKS

Table of n, a(n) for n=1..17.


MATHEMATICA

Join[{0}, Select[ Range@10000, FreeQ[ IntegerDigits[3^# ], 2] &]


PROG

(MAGMA) [n: n in [0..1000]  not 2 in Intseq(3^n)]; // Vincenzo Librandi, May 06 2015
(PARI) isok(n) = ! vecsearch(Set(digits(3^n)), 2); \\ Michel Marcus, Feb 09 2018


CROSSREFS

Cf. similar sequences listed in A131613.
Cf. A007377.
Sequence in context: A193846 A255908 A011402 * A196000 A044952 A047466
Adjacent sequences: A131622 A131623 A131624 * A131626 A131627 A131628


KEYWORD

base,fini,nonn,more


AUTHOR

Shyam Sunder Gupta, Sep 01 2007


EXTENSIONS

Initial 0 added and Mathematica code adapted by Vincenzo Librandi, May 06 2015


STATUS

approved



