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A097211 a(n) = the number of sets of distinct positive integers with a least common multiple of A025487(n), i.e., A076078(A025487(n)). 1
1, 2, 4, 10, 8, 44, 16, 184, 218, 32, 400, 752, 3748, 64, 3392, 3040, 61064, 128, 27904, 253808, 12224, 64594, 57856, 981520, 256, 226304, 16450240, 49024, 16700300, 954368, 15722528, 512, 1822720, 1055953664, 196352, 4278006328, 15499264 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

The sequence A025487 contains the least number of each prime signature.

Sequence is a rearrangement of A097210 unless two or more members of A025487 are LCMs of an identical number of sets of distinct positive integers.

LINKS

Table of n, a(n) for n=1..37.

MATHEMATICA

f[n_] := Block[{d = Divisors[n]}, Plus @@ (MoebiusMu[n/d](2^DivisorSigma[0, d] - 1))]; PrimeExponents[n_] := Flatten[ Table[ # [[2]], {1}] & /@ FactorInteger[n]]; lpe = {}; ln = {1}; Do[pe = Sort[PrimeExponents[n]]; If[ Position[lpe, pe] == {}, AppendTo[lpe, pe]; AppendTo[ln, f[n]]], {n, 1000}]; ln (* Robert G. Wilson v, Aug 14 2004 *)

CROSSREFS

Sequence in context: A178729 A124108 A173824 * A092945 A056376 A185372

Adjacent sequences:  A097208 A097209 A097210 * A097212 A097213 A097214

KEYWORD

nonn

AUTHOR

Matthew Vandermast, Aug 09 2004

EXTENSIONS

Second comment edited by Matthew Vandermast, Oct 21 2008

STATUS

approved

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Last modified March 26 06:49 EDT 2017. Contains 284111 sequences.