A030703 Decimal expansion of 7^n contains no zeros (probably finite).

0, 1, 2, 3, 6, 7, 10, 11, 19, 35

Offset: 1

Author

Eric W. Weisstein

Keywords

• nonn
• base

Comments

No additional terms up to 20000. - Harvey P. Dale, Oct 02 2013

Links

• W. Schneider, NoZeros: Powers n^k without Digit Zero [Cached copy]
• Eric Weisstein's World of Mathematics, Zero

Crossrefs

Cf. A195942, A195943, A195944, A195945, A195946, A195908, A007377, A008839, A030700, A030701, A030702, A030704, A030705, A030706.

Programs

Magma

[n: n in [0..500] | not 0 in Intseq(7^n)]; // Vincenzo Librandi, Mar 08 2014

Mathematica

Select[Range[0,100],DigitCount[7^#,10,0]==0&] (* Harvey P. Dale, Oct 02 2013 *)

PARI

for( n=0, 9999, is_A052382(7^n) && print1(n, ", "))  \\ M. F. Hasler, Sep 25 2011

Formula

A030703 = A000420^(-1)(A052382) as a set, where f^(-1)(Y) = { x : f(x) in Y}.

A030703 = A000420^(-1) o A195908 as a function. - M. F. Hasler, Sep 25 2011

Extensions

Initial term 0 inserted by M. F. Hasler, Sep 25 2011