

A035062


Numbers n such that 2^n does not contain the digit 7.


1



0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 16, 18, 19, 22, 23, 25, 28, 33, 41, 42, 49, 50, 54, 61, 71
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,3


COMMENTS

It is conjectured that 71 is the last term.


LINKS

Table of n, a(n) for n=1..30.


MATHEMATICA

Join[{0}, Select[ Range@10000, FreeQ[ IntegerDigits[2^# ], 7] &]  Shyam Sunder Gupta, Sep 01 2007


PROG

(MAGMA) [n: n in [0..1000]  not 7 in Intseq(2^n) ]; // Vincenzo Librandi, May 06 2015
(PARI) is(n)=!#select(k>k==7, Set(digits(2^n))) \\ Charles R Greathouse IV, May 06 2015


CROSSREFS

Cf. similar sequences listed in A035064.
Sequence in context: A061773 A125007 A290748 * A032964 A033066 A246075
Adjacent sequences: A035059 A035060 A035061 * A035063 A035064 A035065


KEYWORD

nonn,base,fini


AUTHOR

Patrick De Geest, Nov 15 1998


EXTENSIONS

Edited by N. J. A. Sloane, May 21 2008 at the suggestion of R. J. Mathar
Initial 0 added and Mathematica code adapted by Vincenzo Librandi, May 06 2015


STATUS

approved



