login
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
OFFSET
1,3
COMMENTS
I conjecture that 59 is the last term.
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
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