A366519 Largest odd divisor of n which is <= sqrt(n).
1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 3, 1, 1, 3, 1, 1, 3, 1, 1, 3, 1, 1, 3, 5, 1, 3, 1, 1, 5, 1, 1, 3, 1, 5, 3, 1, 1, 3, 5, 1, 3, 1, 1, 5, 1, 1, 3, 7, 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, 9, 1, 1, 7, 5, 1, 3, 1, 1, 9, 7, 1, 3, 1, 5, 3, 1, 7, 9, 5
Offset: 1
Keywords
Links
- Andrew Howroyd, Table of n, a(n) for n = 1..10000
Programs
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Mathematica
Table[Last[Select[Divisors[n], # <= Sqrt[n] && OddQ[#] &]], {n, 100}] -
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