A064564 Reciprocal of n terminates with an infinite repetition of digit 5. Multiples of 10 are omitted.

18, 1152, 28125, 73728, 4718592, 301989888, 439453125, 19327352832, 1236950581248, 6866455078125, 79164837199872, 5066549580791808, 107288360595703125, 324259173170675712, 20752587082923245568

Offset

1,1

References

A. H. Beiler, Recreations in the Theory of Numbers, Dover, N.Y., 1964, pp. 73-82.

Links

Table of n, a(n) for n=1..15.

Index entries for sequences related to decimal expansion of 1/n

Formula

Numbers of the form 9*2^(6i-5) and 9*5^(6i-1) [i>0].

Example

1/28125 = 0.000035555555555...

Mathematica

With[{nn=20}, Take[Sort[Flatten[Table[{9 2^(6n-5), 9 5^(6n-1)}, {n, nn}]]], nn]] (* Harvey P. Dale, Oct 22 2013 *)

Crossrefs

Cf. A064560, A064561, A064562, A064563, A064565, A064566, A064567.

Sequence in context: A052135 A033518 A333006 * A152933 A360602 A177602

Adjacent sequences: A064561 A064562 A064563 * A064565 A064566 A064567

Keyword

nonn,base

Author

Patrick De Geest, Sep 20 2001

Extensions

More terms from James A. Sellers, Sep 28 2001

Status

approved