OFFSET
1,2
COMMENTS
a(n) = n for squarefree n; otherwise, a(n) > n. - Ivan Neretin, May 13 2015
Dirichlet inverse of A062953. - Werner Schulte, Oct 25 2018
LINKS
Ivan Neretin, Table of n, a(n) for n = 1..10000
FORMULA
Multiplicative with a(p^e) = p(p+1)^(e-1). - David W. Wilson, Sep 01 2001
Sum_{k=1..n} a(k) ~ c * n^2, where c = (1/2) * Product_{p prime} (1 + 1/(p^3 - p^2 - p)) = A104141/A005596 = 0.8128327996... . - Amiram Eldar, Oct 23 2022
MATHEMATICA
Table[{pp, aa} = Transpose[FactorInteger[n]]; Times @@ (pp*(pp + 1)^(aa - 1)), {n, 70}] (* Ivan Neretin, May 13 2015 *)
PROG
(PARI) a(n) = {my(f=factor(n)); for (i=1, #f~, p= f[i, 1]; f[i, 1] = p*(p+1)^(f[i, 2]-1); f[i, 2] = 1); factorback(f); } \\ Michel Marcus, Feb 26 2015
CROSSREFS
KEYWORD
nonn,mult
AUTHOR
EXTENSIONS
More terms from David W. Wilson, Aug 29 2001
STATUS
approved