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A093863 Unitary sigma-unitary phi super perfect numbers: USUP(USUP(n))= n/k for some integer k. 0
1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 16, 17, 18, 20, 24, 34, 36, 40, 48, 68, 72, 80, 136, 144, 256, 257, 272, 514, 768, 1028, 1280, 2056, 2304, 2808, 4112, 4320, 4352 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

USUP(.)= A109712(.). Where k values are 1, they define fixed points of the function USUP(USUP(n)). k values larger than 1 exist, for example USUP(USUP(4320))= 4320/2.

MAPLE

for n from 1 to 20000 do if n mod A109712(A109712(n)) = 0 then printf("%d, ", n); end if; end do:

CROSSREFS

Cf. A092760.

Sequence in context: A029509 A048645 A173786 * A091902 A067698 A110495

Adjacent sequences:  A093860 A093861 A093862 * A093864 A093865 A093866

KEYWORD

nonn

AUTHOR

Yasutoshi Kohmoto (zbi74583(AT)boat.zero.ad.jp), May 11 2004

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Last modified February 15 07:22 EST 2012. Contains 205706 sequences.