OFFSET
1,2
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
FORMULA
Multiplicative with a(p^e) = ((p+1)^(e+1)-1)/p. - David W. Wilson, Sep 01 2001
MATHEMATICA
f[p_, e_] := ((p + 1)^(e + 1) - 1)/p; a[1] = 1; a[n_] := Times @@ f @@@ FactorInteger[n]; Array[a, 100] (* Amiram Eldar, Oct 23 2022 *)
PROG
(PARI) a(n) = {my(f = factor(n)); prod(i = 1, #f~, ((f[i, 1] + 1)^(f[i, 2] + 1) - 1)/f[i, 1]); } \\ Amiram Eldar, Oct 23 2022
CROSSREFS
KEYWORD
nonn,mult
AUTHOR
EXTENSIONS
More terms from David W. Wilson, Aug 29 2001
STATUS
approved