A131625 Numbers k such that decimal expansion of 3^k contains no 2.

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

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: A341107 A344075 A011402 * A196000 A044952 A352831

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