A366520 Largest odd divisor of n which is < sqrt(n), for n >= 2; a(1) = 1.

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 3, 1, 1, 3, 1, 1, 3, 1, 1, 3, 1, 1, 3, 1, 1, 5, 1, 1, 3, 1, 5, 3, 1, 1, 3, 5, 1, 3, 1, 1, 5, 1, 1, 3, 1, 5, 3, 1, 1, 3, 5, 7, 3, 1, 1, 5, 1, 1, 7, 1, 5, 3, 1, 1, 3, 7, 1, 3, 1, 1, 5, 1, 7, 3, 1, 5, 3, 1, 1, 7, 5, 1, 3, 1, 1, 9, 7, 1, 3, 1, 5, 3, 1, 7, 9, 5

Offset

1,12

Links

Andrew Howroyd, Table of n, a(n) for n = 1..10000

Mathematica

Join[{1}, Table[Last[Select[Divisors[n], # < Sqrt[n] && OddQ[#] &]], {n, 2, 100}]]

Prog

(PARI) a(n) = {my(m=1); fordiv(n/2^valuation(n, 2), d, if(d^2 < n, m=max(m, d))); m} \\ Andrew Howroyd, Oct 11 2023

Crossrefs

Cf. A000265, A060775, A093803, A366519.

Sequence in context: A111625 A109007 A132951 * A366519 A353517 A353487

Adjacent sequences: A366517 A366518 A366519 * A366521 A366522 A366523

Keyword

nonn

Author

Ilya Gutkovskiy, Oct 11 2023

Status

approved