OFFSET
1,2
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..10000
FORMULA
a(n)*A204455(n) = n.
a(n) = EvenPart(n)*A003557(OddPart(n)). - Peter Munn, Oct 09 2022
Multiplicative with a(p^e) = p^(e-1) if p > 2 and a(2^e) = 2^e. - Amiram Eldar, Oct 10 2022
EXAMPLE
n = A204455(n)*a(n): 1 = 1*1, 2 = 1*2, 3 = 3*1, 4 = 1*4, 5 = 5*1, 6 = 3*2.
MATHEMATICA
f[p_, e_] := p^(e - If[p == 2, 0, 1]); a[n_] := Times @@ f @@@ FactorInteger[n]; Array[a, 100] (* Amiram Eldar, Oct 10 2022 *)
PROG
(Magma) [(2*n)/&*PrimeDivisors(2*n): n in [1..100]];
(Magma) [n/&*[d: d in Divisors(n) | d*#[m: m in [0..n-1] | -m^d mod d eq m] eq
#[m: m in [0..n-1] | m^d mod d eq m]]: n in [1..100]];
CROSSREFS
KEYWORD
nonn,mult,easy
AUTHOR
Juri-Stepan Gerasimov, Oct 09 2022
STATUS
approved