1,3

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

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

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

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

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

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

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

nonn,mult

Ilya Gutkovskiy, Feb 03 2021

approved