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A245530
a(n) = smallest square which is the product of a minimal set of distinct numbers not less than n.
4
1, 36, 144, 4, 400, 576, 784, 14400, 9, 32400, 4356, 3600, 6084, 1587600, 129600, 16, 10404, 11664, 23104, 14400, 15876, 17424, 33856, 20736, 25, 876096, 25401600, 1254400, 53824, 44100, 61504, 57600, 85377600, 4161600, 2822400, 36, 136900, 116964, 97344
OFFSET
1,2
COMMENTS
a(n) = product(A245499(n,k)): k=1..A066400(n)), product of n-th row in A245499;
A066401(n) = sqrt(a(n)), a(n) = A066401(n)^2;
a(n) mod n = 0; a(n) mod A006255(n) = 0.
LINKS
Peter Kagey, Table of n, a(n) for n = 1..1000 (First 125 terms from Reinhard Zumkeller)
MATHEMATICA
Table[k = 0; While[Length@ # == 0 &@ Set[f, Select[Rest@ Subsets@ Range@ k, IntegerQ@ Sqrt[n (Times @@ # &[n + #])] &]], k++]; If[IntegerQ@ Sqrt@ n, k = {n}, k = n + Prepend[First@ f, 0]]; Times @@ k, {n, 22}] (* Michael De Vlieger, Oct 26 2016 *)
PROG
(Haskell)
a245530 = product . a245499_row
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Jul 25 2014
STATUS
approved