A193322 Sum of even divisors of lambda(n).

0, 0, 2, 2, 6, 2, 8, 2, 8, 6, 12, 2, 24, 8, 6, 6, 30, 8, 26, 6, 8, 12, 24, 2, 36, 24, 26, 8, 48, 6, 48, 14, 12, 30, 24, 8, 78, 26, 24, 6, 84, 8, 64, 12, 24, 24, 48, 6, 64, 36, 30, 24, 84, 26, 36, 8, 26, 48, 60, 6, 144, 48, 8, 30, 24, 12, 96, 30, 24, 24, 96, 8, 182, 78, 36, 26, 48, 24, 112, 6, 80, 84, 84, 8, 30, 64

Offset: 1

Author

Michel Lagneau, Jul 22 2011

Keywords

• nonn

Comments

Lambda is the function in A002322.

Examples

			a(17) = 30 because lambda(17) = 16 and the sum of the 4 even divisors { 2, 4, 8, 16} is 30.
		

Links

• Antti Karttunen, Table of n, a(n) for n = 1..16384

Crossrefs

Cf. A002322, A146076, A191613.

Programs

Mathematica

Table[Total[Select[Divisors[CarmichaelLambda[n]], EvenQ[ # ]&]], {n, 62}]
(* Second program: *)
Array[DivisorSum[CarmichaelLambda@ #, # &, EvenQ] &, 86] (* Michael De Vlieger, Dec 04 2017 *)

PARI

a(n) = sumdiv(lcm(znstar(n)[2]), d, d*(1-(d%2))); \\ Michel Marcus, Mar 18 2016

Formula

a(n) = A146076(A002322(n)). - Michel Marcus, Mar 18 2016

Extensions

More terms from Antti Karttunen, Dec 04 2017