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

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Last modified March 29 15:16 EDT 2020. Contains 333107 sequences. (Running on oeis4.)