A377845 Numbers that have more than one odd exponent larger than 1 in their prime factorization.

216, 864, 1000, 1080, 1512, 1944, 2376, 2744, 2808, 3000, 3375, 3456, 3672, 4000, 4104, 4320, 4968, 5400, 6048, 6264, 6696, 6750, 7000, 7560, 7776, 7992, 8232, 8856, 9000, 9261, 9288, 9504, 9720, 10152, 10584, 10648, 10976, 11000, 11232, 11448, 11880, 12000, 12744, 13000

Offset: 1

Author

Amiram Eldar, Nov 09 2024

Keywords

• nonn
• easy

Comments

The asymptotic density of this sequence is 1 - Product_{p prime} (1 - 1/(p^2*(p+1))) * (1 + Sum_{p prime} (1/(p^3+p^2-1))) = 0.0035024748296318122535... .

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Complement of the union of A335275 and A377844.

Subsequence of A295661.

Subsequences: A162142, A179671, A190011.

Cf. A065465.

Programs

Mathematica

q[n_] := Count[FactorInteger[n][[;; , 2]], _?(# > 1 && OddQ[#] &)] > 1; Select[Range[13000], q]

PARI

is(k) = #select(x -> x>1 && x%2, factor(k)[, 2]) > 1;