A324910 Multiplicative with a(p^e) = (2^e)-1.

1, 1, 1, 3, 1, 1, 1, 7, 3, 1, 1, 3, 1, 1, 1, 15, 1, 3, 1, 3, 1, 1, 1, 7, 3, 1, 7, 3, 1, 1, 1, 31, 1, 1, 1, 9, 1, 1, 1, 7, 1, 1, 1, 3, 3, 1, 1, 15, 3, 3, 1, 3, 1, 7, 1, 7, 1, 1, 1, 3, 1, 1, 3, 63, 1, 1, 1, 3, 1, 1, 1, 21, 1, 1, 3, 3, 1, 1, 1, 15, 15, 1, 1, 3, 1, 1, 1, 7, 1, 3, 1, 3, 1, 1, 1, 31, 1, 3, 3, 9, 1, 1, 1, 7, 1

Offset: 1

Author

Antti Karttunen, Apr 14 2019

Keywords

• nonn
• mult

Links

• Antti Karttunen, Table of n, a(n) for n = 1..65537
• Index entries for sequences computed from exponents in factorization of n

Crossrefs

Cf. A000225, A156552, A246674, A322993, A324911.

Programs

Mathematica

Array[Times @@ (2^(FactorInteger[#][[All, -1]]) - 1) &, 105] (* Michael De Vlieger, Apr 14 2019 *)

PARI

A324910(n) = factorback(apply(e -> -1+(2^e), factor(n)[,2]~));

Formula

Multiplicative with a(p^e) = A000225(e).

Multiplicative with a(p^e) = A322993(p^e).

a(n) = A246674(A156552(n)).