A131617 Numbers k such that the decimal expansion of 3^k contains no 5.

0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 14, 15, 16, 17, 18, 19, 20, 23, 25, 29, 31, 41, 44, 52, 58, 81, 91

Offset

1,3

Comments

I conjecture that 91 is the last term.

Links

Table of n, a(n) for n=1..27.

Mathematica

Join[{0}, Select[ Range@10000, FreeQ[ IntegerDigits[3^# ], 5] &]

Prog

(Magma) [n: n in [0..1000] | not 5 in Intseq(3^n) ]; // Vincenzo Librandi, May 06 2015

Crossrefs

Cf. similar sequences listed in A131613.

Cf. A007377.

Sequence in context: A307360 A283455 A283364 * A214321 A320318 A005577

Adjacent sequences: A131614 A131615 A131616 * A131618 A131619 A131620

Keyword

base,fini,nonn

Author

Shyam Sunder Gupta, Sep 01 2007

Extensions

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

Status

approved