A193322 - OEIS

%I #16 Dec 05 2017 04:08:32

%S 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,

%T 6,48,14,12,30,24,8,78,26,24,6,84,8,64,12,24,24,48,6,64,36,30,24,84,

%U 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

%N Sum of even divisors of lambda(n).

%C Lambda is the function in A002322.

%H Antti Karttunen, <a href="/A193322/b193322.txt">Table of n, a(n) for n = 1..16384</a>

%F a(n) = A146076(A002322(n)). - _Michel Marcus_, Mar 18 2016

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

%t Table[Total[Select[Divisors[CarmichaelLambda[n]], EvenQ[ # ]&]], {n, 62}]

%t (* Second program: *)

%t Array[DivisorSum[CarmichaelLambda@ #, # &, EvenQ] &, 86] (* _Michael De Vlieger_, Dec 04 2017 *)

%o (PARI) a(n) = sumdiv(lcm(znstar(n)[2]), d, d*(1-(d%2))); \\ _Michel Marcus_, Mar 18 2016

%Y Cf. A002322, A146076, A191613.

%K nonn

%O 1,3

%A _Michel Lagneau_, Jul 22 2011

%E More terms from _Antti Karttunen_, Dec 04 2017