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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

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Last modified January 20 14:40 EST 2019. Contains 319333 sequences. (Running on oeis4.)