OFFSET
1,3
COMMENTS
Lambda is the function in A002322.
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..16384
FORMULA
EXAMPLE
a(17) = 30 because lambda(17) = 16 and the sum of the 4 even divisors { 2, 4, 8, 16} is 30.
MATHEMATICA
Table[Total[Select[Divisors[CarmichaelLambda[n]], EvenQ[ # ]&]], {n, 62}]
(* Second program: *)
Array[DivisorSum[CarmichaelLambda@ #, # &, EvenQ] &, 86] (* Michael De Vlieger, Dec 04 2017 *)
PROG
(PARI) a(n) = sumdiv(lcm(znstar(n)[2]), d, d*(1-(d%2))); \\ Michel Marcus, Mar 18 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Lagneau, Jul 22 2011
EXTENSIONS
More terms from Antti Karttunen, Dec 04 2017
STATUS
approved