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A366523
Largest square divisor of n which is <= sqrt(n).
2
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 4, 1, 1, 1, 4, 1, 1, 1, 4, 1, 1, 1, 4, 1, 1, 1, 4, 1, 1, 1, 4, 1, 1, 1, 4, 1, 1, 1, 4, 1, 1, 1, 4, 1, 1, 1, 4, 1, 1, 1, 4, 1, 1, 1, 4, 1, 1, 1, 4, 1, 1, 1, 4, 1, 1, 1, 4, 1, 1, 1, 4, 1, 1, 1, 4, 9, 1, 1, 4, 1, 1, 1, 4, 1, 9, 1, 4, 1, 1, 1, 4, 1, 1, 9, 4
OFFSET
1,16
LINKS
MATHEMATICA
Table[Last[Select[Divisors[n], # <= Sqrt[n] && IntegerQ[Sqrt[#]] &]], {n, 100}]
PROG
(PARI) a(n) = {my(m=1); fordiv(sqrtint(n/core(n)), d, if(d^4 <= n, m=max(m, d))); m^2} \\ Andrew Howroyd, Oct 11 2023
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Oct 11 2023
STATUS
approved