OFFSET
1,2
COMMENTS
All terms are squarefree numbers (A005117).
a(n) >> exp(n/2); presumably finite. If a(6) exists then a(6) > 10^200000. - Charles R Greathouse IV, Jul 13 2024
FORMULA
From Alois P. Heinz, Jul 13 2024: (Start)
EXAMPLE
714 is a term because 714*715 = 510510 = A002110(7) = 2*3*5*7*11*13*17.
MATHEMATICA
nn = 1000; MapIndexed[Set[P[First[#2]], #1] &, FoldList[Times, Prime@ Range[nn]]]; Monitor[Reap[Do[(d = Floor@ Sqrt[#]; If[Divisible[#, d], Sow[d]]) &[P[i]], {i, nn}]][[-1, 1]], i] (* Michael De Vlieger, Jul 14 2024 *)
CROSSREFS
KEYWORD
nonn,hard
AUTHOR
David James Sycamore and Michael De Vlieger, Jul 13 2024
STATUS
approved