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A193322 Sum of even divisors of lambda(n). 3
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Lambda is the function in A002322.

LINKS

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

FORMULA

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

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

Cf. A002322, A146076, A191613.

Sequence in context: A167556 A221438 A327991 * A165460 A242649 A294876

Adjacent sequences:  A193319 A193320 A193321 * A193323 A193324 A193325

KEYWORD

nonn

AUTHOR

Michel Lagneau, Jul 22 2011

EXTENSIONS

More terms from Antti Karttunen, Dec 04 2017

STATUS

approved

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Last modified August 8 08:27 EDT 2020. Contains 336293 sequences. (Running on oeis4.)