OFFSET
1,2
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
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
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