OFFSET
1,1
COMMENTS
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..10000
Michael De Vlieger, Numbers k for which floor(log k / log lpf(k)) <= bigomega(k), 2024.
EXAMPLE
36 is not in the sequence since 2^5 < 36, Omega(32) = 5, but Omega(36) = 4.
72 is not in the sequence since 2^6 < 72, but Omega(72) = 5.
225 is in the sequence since 3^4 < 225, Omega(81) = Omega(225) = 4.
441 is not in the sequence since 3^5 < 441, Omega(243) = 5, but Omega(441) = 4, etc.
MATHEMATICA
Select[With[{nn = 200000},
Rest@ Select[
Union@ Flatten@ Table[a^2*b^3, {b, Surd[nn, 3]}, {a, Sqrt[nn/b^3]}],
Not@*PrimePowerQ] ],
Function[{n, k},
NoneTrue[FactorInteger[n][[All, 1]],
Floor@ Log[#, n] > k &]] @@ {#, PrimeOmega[#]} &]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Michael De Vlieger, Nov 02 2024
STATUS
approved