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A003971
Inverse Möbius transform of A003960.
1
1, 2, 3, 3, 4, 6, 5, 4, 7, 8, 7, 9, 8, 10, 12, 5, 10, 14, 11, 12, 15, 14, 13, 12, 13, 16, 15, 15, 16, 24, 17, 6, 21, 20, 20, 21, 20, 22, 24, 16, 22, 30, 23, 21, 28, 26, 25, 15, 21, 26, 30, 24, 28, 30, 28, 20, 33, 32, 31, 36, 32, 34, 35, 7, 32, 42, 35, 30, 39, 40, 37, 28, 38, 40
OFFSET
1,2
LINKS
N. J. A. Sloane, Transforms.
FORMULA
Multiplicative with a(p^e) = e+1 if p = 2; (((p+1)/2)^(e+1) - 1)/((p-1)/2) if p > 2. - David W. Wilson, Sep 01 2001
MATHEMATICA
f[p_, e_] := (((p + 1)/2)^(e + 1) - 1)/((p - 1)/2); f[2, e_] := e + 1; a[1] = 1; a[n_] := Times @@ f @@@ FactorInteger[n]; Array[a, 100] (* Amiram Eldar, Dec 06 2022 *)
CROSSREFS
Cf. A003960.
Sequence in context: A347712 A159999 A003977 * A349371 A282442 A200668
KEYWORD
nonn,easy,mult
AUTHOR
EXTENSIONS
More terms from Reiner Martin, Aug 15 2001
Formula corrected by Sean A. Irvine, Sep 26 2015
STATUS
approved