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A193169 Number of odd divisors of lambda(n). 4
1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 2, 1, 2, 2, 1, 1, 1, 2, 3, 1, 2, 2, 2, 1, 2, 2, 3, 2, 2, 1, 4, 1, 2, 1, 2, 2, 3, 3, 2, 1, 2, 2, 4, 2, 2, 2, 2, 1, 4, 2, 1, 2, 2, 3, 2, 2, 3, 2, 2, 1, 4, 4, 2, 1, 2, 2, 4, 1, 2, 2, 4, 2, 3, 3, 2, 3, 4, 2, 4, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,7

COMMENTS

Lambda is the function in A002322.

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = A001227(A002322(n)). - Michel Marcus, Mar 18 2016

EXAMPLE

a(19) = 3 because lambda(19) = 18 and the 3 odd divisors are {1, 3, 9}.

MATHEMATICA

f[n_] := Block[{d = Divisors[CarmichaelLambda[n]]}, Count[OddQ[d], True]]; Table[f[n], {n, 80}]

PROG

(Haskell)

a193169 = length . filter odd . a027750_row . a002322

-- Reinhard Zumkeller, Sep 02 2014

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

CROSSREFS

Cf. A002322.

Cf. A027750, A001227.

Sequence in context: A231776 A055734 A295660 * A193453 A227944 A095772

Adjacent sequences:  A193166 A193167 A193168 * A193170 A193171 A193172

KEYWORD

nonn

AUTHOR

Michel Lagneau, Jul 22 2011

STATUS

approved

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Last modified October 22 22:35 EDT 2021. Contains 348180 sequences. (Running on oeis4.)