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A195908 Powers of 7 which have no zero in their decimal expansion. 22
1, 7, 49, 343, 117649, 823543, 282475249, 1977326743, 11398895185373143, 378818692265664781682717625943 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Probably finite. Is 378818692265664781682717625943 the largest term?

LINKS

Table of n, a(n) for n=1..10.

M. F. Hasler, Zeroless powers, OEIS Wiki, Mar 07 2014

C. Rivera, Puzzle 607. A zeroless Prime power, on primepuzzles.net, Sept. 24, 2011.

W. Schneider, NoZeros: Powers n^k without Digit Zero (local copy of www.wschnei.de/digit-related-numbers/nozeros.html), as of Jan 30 2003.

FORMULA

a(n) = 7^A030703(n).

A000420 intersect A052382.

PROG

(PARI) for( n=1, 9999, is_A052382(7^n) && print1(7^n, ", "))

(MAGMA) [7^n: n in [0..3*10^4] | not 0 in Intseq(7^n)]; // Bruno Berselli, Sep 26 2011

CROSSREFS

Cf. A195942, A195943, A195944, A195945, A195946, A195948, A007377, A008839, A030700, A030701, A030702, A030703, A030704, A030705, A030706.

Sequence in context: A206453 A000420 A050737 * A033143 A024582 A024587

Adjacent sequences:  A195905 A195906 A195907 * A195909 A195910 A195911

KEYWORD

nonn,base,fini

AUTHOR

M. F. Hasler, Sep 25 2011

STATUS

approved

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Last modified June 25 06:13 EDT 2017. Contains 288709 sequences.