A193169 Number of odd divisors of lambda(n).

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

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