A193254 Sum of odd divisors of lambda(n).

1, 1, 1, 1, 1, 1, 4, 1, 4, 1, 6, 1, 4, 4, 1, 1, 1, 4, 13, 1, 4, 6, 12, 1, 6, 4, 13, 4, 8, 1, 24, 1, 6, 1, 4, 4, 13, 13, 4, 1, 6, 4, 32, 6, 4, 12, 24, 1, 32, 6, 1, 4, 14, 13, 6, 4, 13, 8, 30, 1, 24, 24, 4, 1, 4, 6, 48, 1, 12, 4, 48, 4, 13, 13, 6, 13, 24, 4, 56, 1, 40, 6, 42, 4, 1, 32, 8, 6, 12, 4, 4, 12, 24, 24, 13, 1, 4, 32, 24, 6, 31, 1, 72, 4, 4

Offset

1,7

Comments

Lambda is the function in A002322.

Links

Antti Karttunen, Table of n, a(n) for n = 1..10000

Formula

a(n) = A000593(A002322(n)).

Example

a(19) = 13 because lambda(19) = 18 and the sum of the 3 odd divisors {1, 3, 9} is 13.

Mathematica

Table[Total[Select[Divisors[CarmichaelLambda[n]], OddQ[ # ]&]], {n, 67}]

Prog

(PARI) a(n) = sumdiv(lcm(znstar(n)[2]), d, d*(d%2));

Crossrefs

Cf. A002322, A000593, A193169, A193454.

Sequence in context: A095666 A257231 A196757 * A193454 A368921 A322819

Adjacent sequences: A193251 A193252 A193253 * A193255 A193256 A193257

Keyword

nonn

Author

Michel Lagneau, Jul 22 2011

Extensions

More terms from Antti Karttunen, Aug 22 2017

Status

approved