A131618 Numbers k such that the decimal expansion of 3^k contains no 4.

0, 1, 2, 3, 4, 6, 7, 8, 9, 22, 33, 34, 38, 46, 49, 75, 106

Offset

1,3

Comments

I conjecture that 106 is the last term.

Links

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

Mathematica

Join[{0}, Select[ Range@10000, FreeQ[ IntegerDigits[3^# ], 4] &]

Prog

(Magma) [n: n in [0..1000] | not 4 in Intseq(3^n)]; // Vincenzo Librandi, May 06 2015

Crossrefs

Cf. similar sequences listed in A131613.

Cf. A007377.

Sequence in context: A036796 A209643 A039123 * A144111 A039257 A345914

Adjacent sequences: A131615 A131616 A131617 * A131619 A131620 A131621

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