A069858 1/n has period 4 in base 10.

101, 202, 303, 404, 505, 606, 808, 909, 1010, 1111, 1212, 1515, 1616, 1818, 2020, 2222, 2424, 2525, 3030, 3232, 3333, 3636, 4040, 4444, 4545, 4848, 5050, 5555, 6060, 6464, 6666, 7272, 7575, 8080, 8888, 9090, 9696, 9999, 10100, 11110, 12120, 12625

Offset

1,1

Links

Table of n, a(n) for n=1..42.

Formula

Numbers of the form a*b*c where a is in {101, 303, 909, 1111, 3333, 9999}, b is a power of 2 and c is a power of 5.

Example

1212 is in the sequence since 1/1212=0.0008250825082508250825082508250....

Mathematica

Select[Range[13000], Length[RealDigits[1/#][[1, -1]]]==4&] (* Harvey P. Dale, Jun 30 2017 *)

Crossrefs

Cf. A027894, A003592, A069105, A070021, A070022, A070023.

Sequence in context: A134970 A081365 A138131 * A357033 A319744 A303575

Adjacent sequences: A069855 A069856 A069857 * A069859 A069860 A069861

Keyword

base,nonn

Author

Henry Bottomley, May 02 2002

Status

approved