A331739 a(n) is n minus its largest odd divisor.

0, 1, 0, 3, 0, 3, 0, 7, 0, 5, 0, 9, 0, 7, 0, 15, 0, 9, 0, 15, 0, 11, 0, 21, 0, 13, 0, 21, 0, 15, 0, 31, 0, 17, 0, 27, 0, 19, 0, 35, 0, 21, 0, 33, 0, 23, 0, 45, 0, 25, 0, 39, 0, 27, 0, 49, 0, 29, 0, 45, 0, 31, 0, 63, 0, 33, 0, 51, 0, 35, 0, 63, 0, 37, 0, 57, 0, 39, 0, 75, 0, 41, 0, 63, 0, 43, 0, 77, 0, 45, 0, 69, 0, 47

Offset

1,4

Links

Antti Karttunen, Table of n, a(n) for n = 1..16384

Formula

a(n) = n - A000265(n).

Maple

A331739 := proc(n)
    n-A000265(n) ;
end proc:
seq(A331739(n), n=1..40) ; # R. J. Mathar, Jan 24 2022

Mathematica

a[n_] := n - n/2^IntegerExponent[n, 2];
Table[a[n], {n, 1, 100}] (* Jean-François Alcover, Oct 19 2023 *)

Prog

(PARI) A331739(n) = (n-(n>>valuation(n, 2)));
(Python)
def A331739(n): return n-(n>>(~n & n-1).bit_length()) # Chai Wah Wu, Jul 01 2022

Crossrefs

Cf. A000265, A006519, A007814, A135481.

Cf. A129527 (even bisection).

Sequence in context: A132748 A022901 A348215 * A356169 A055945 A138123

Adjacent sequences: A331736 A331737 A331738 * A331740 A331741 A331742

Keyword

nonn,easy

Author

Antti Karttunen, Feb 02 2020

Status

approved