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A341042 Multiplicative projection of odd part of n. 0
1, 1, 3, 1, 5, 3, 7, 1, 6, 5, 11, 3, 13, 7, 15, 1, 17, 6, 19, 5, 21, 11, 23, 3, 10, 13, 9, 7, 29, 15, 31, 1, 33, 17, 35, 6, 37, 19, 39, 5, 41, 21, 43, 11, 30, 23, 47, 3, 14, 10, 51, 13, 53, 9, 55, 7, 57, 29, 59, 15, 61, 31, 42, 1, 65, 33, 67, 17, 69, 35, 71, 6, 73, 37, 30 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..75.

Index entries for sequences computed from indices in prime factorization

Index entries for sequences computed from exponents in factorization of n

FORMULA

a(n) = A000026(A000265(n)).

a(n) = A000026(n) if n odd, a(n) = a(n/2) if n even.

EXAMPLE

a(54) = a(2 * 3^3) = 3 * 3 = 9.

MAPLE

a:= n-> mul(`if`(i[1]=2, 1, i[1]*i[2]), i=ifactors(n)[2]):

seq(a(n), n=1..75);  # Alois P. Heinz, Feb 03 2021

MATHEMATICA

a[n_] := Times @@ (#[[1]] #[[2]] & /@ FactorInteger[n/2^IntegerExponent[n, 2]]); Table[a[n], {n, 75}]

CROSSREFS

Cf. A000026, A000079 (positions of 1's), A000265, A056911 (fixed points), A204455.

Sequence in context: A204455 A318653 A161820 * A116528 A081431 A053641

Adjacent sequences:  A341039 A341040 A341041 * A341043 A341044 A341045

KEYWORD

nonn,mult

AUTHOR

Ilya Gutkovskiy, Feb 03 2021

STATUS

approved

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Last modified June 15 08:52 EDT 2021. Contains 345048 sequences. (Running on oeis4.)