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A097215
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Numbers n such that A076078(n)=n and bigomega(n) >= 2; or in other words, A097214, excluding powers of 2.
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2
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10, 44, 184, 752, 12224, 49024, 61064, 981520, 12580864, 206158168064, 16492668126208, 1080863908958322688, 18374686467592175488, 885443715520878608384, 4703919738602662723328
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| A076078(n) equals the number of sets of distinct positive integers with a least common multiple of n.
If 3*2^m-1 is an odd prime then 2^m*(3*2^m-1) is in the sequence. [From Farideh Firoozbakht (mymontain(AT)yahoo.com), May 03 2009]
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EXAMPLE
| For example, there are 184 sets of distinct positive integers with a least common multiple of 184.
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MATHEMATICA
| f[n_] := Block[{d = Divisors[n]}, Plus @@ (MoebiusMu[n/d](2^DivisorSigma[0, d] - 1))]; t = Union[ Table[ f[n], {n, 28000000}]]; Select[t, f[ # ] == # && !IntegerQ[ Log[2, # ]] &] (from Robert G. Wilson v Aug 17 2004)
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CROSSREFS
| Cf. A097214, A097416.
Cf. A002235. [From Farideh Firoozbakht (mymontain(AT)yahoo.com), May 03 2009]
Sequence in context: A124852 A097416 A076373 * A126397 A164607 A200189
Adjacent sequences: A097212 A097213 A097214 * A097216 A097217 A097218
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KEYWORD
| nonn
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AUTHOR
| Matthew Vandermast (ghodges14(AT)comcast.net), Aug 12 2004
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EXTENSIONS
| More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Aug 18 2004
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