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A121016 Numbers whose binary expansion is properly periodic. 0
3, 7, 10, 15, 31, 36, 42, 45, 54, 63, 127, 136, 153, 170, 187, 204, 221, 238, 255, 292, 365, 438, 511, 528, 561, 594, 627, 660, 682, 693, 726, 759, 792, 825, 858, 891, 924, 957, 990, 1023, 2047, 2080, 2145, 2184, 2210, 2275, 2340, 2405, 2457, 2470, 2535 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

EXAMPLE

For example, 204=(1100 1100)_2 and 292=(100 100 100)_2 belong to the sequence, but 30=(11110)_2 can not be split into repeating periods.

MATHEMATICA

PeriodicQ[n_, base_] := Block[{l = IntegerDigits[n, base]}, MemberQ[ RotateLeft[l, # ] & /@ Most@ Divisors@ Length@l, l]]; Select[ Range@2599, PeriodicQ[ #, 2] &]

CROSSREFS

Sequence in context: A189530 A085145 A143101 * A151733 A088636 A114113

Adjacent sequences:  A121013 A121014 A121015 * A121017 A121018 A121019

KEYWORD

base,easy,nonn

AUTHOR

Jacob Siehler (siehlerj(AT)wlu.edu), Sep 08 2006

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Last modified February 17 13:14 EST 2012. Contains 206031 sequences.