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A193169
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Number of odd divisors of lambda(n).
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4
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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
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OFFSET
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1,7
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COMMENTS
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Lambda is the function in A002322.
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LINKS
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Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
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FORMULA
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a(n) = A001227(A002322(n)). - Michel Marcus, Mar 18 2016
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EXAMPLE
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a(19) = 3 because lambda(19) = 18 and the 3 odd divisors are {1, 3, 9}.
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MATHEMATICA
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f[n_] := Block[{d = Divisors[CarmichaelLambda[n]]}, Count[OddQ[d], True]]; Table[f[n], {n, 80}]
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PROG
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(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
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CROSSREFS
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Cf. A002322.
Cf. A027750, A001227.
Sequence in context: A231776 A055734 A295660 * A193453 A227944 A095772
Adjacent sequences: A193166 A193167 A193168 * A193170 A193171 A193172
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KEYWORD
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nonn
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AUTHOR
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Michel Lagneau, Jul 22 2011
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STATUS
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approved
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