A363828 Highest power of 2 dividing n which is < sqrt(n), for n >= 2; a(1) = 1.

1, 1, 1, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 4, 1, 2, 1, 4, 1, 2, 1, 4, 1, 2, 1, 4, 1, 2, 1, 4, 1, 2, 1, 4, 1, 2, 1, 4, 1, 2, 1, 4, 1, 2, 1, 4, 1, 2, 1, 4, 1, 2, 1, 4, 1, 2, 1, 4, 1, 2, 1, 4, 1, 2, 1, 8, 1, 2, 1, 4, 1, 2, 1, 8, 1, 2, 1, 4, 1, 2, 1, 8, 1, 2, 1, 4, 1, 2, 1, 8, 1, 2, 1, 4

Offset

1,6

Links

Table of n, a(n) for n=1..100.

Mathematica

Join[{1}, Table[Last[Select[Divisors[n], # < Sqrt[n] && IntegerQ[Log[2, #]] &]], {n, 2, 100}]]
a[n_] := 2^Min[IntegerExponent[n, 2], Ceiling[Log2[n]/2] - 1]; a[1] = 1; Array[a, 100] (* Amiram Eldar, Oct 19 2023 *)

Prog

(PARI) a(n) = if (n==1, 1, vecmax(select(x->((x^2 < n) && (2^logint(x, 2)==x)), divisors(n)))); \\ Michel Marcus, Oct 19 2023

Crossrefs

Cf. A006519, A033676, A135517, A363827.

Sequence in context: A161267 A161292 A185219 * A161319 A161253 A161038

Adjacent sequences: A363825 A363826 A363827 * A363829 A363830 A363831

Keyword

nonn

Author

Ilya Gutkovskiy, Oct 19 2023

Status

approved