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

1,1

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

Mathematica

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

Prog

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

Crossrefs

Complement of the union of A335275 and A377844.

Subsequence of A295661.

Subsequences: A162142, A179671, A190011.

Cf. A065465.

Sequence in context: A066890 A242296 A223507 * A135590 A187859 A250137

Adjacent sequences: A377840 A377843 A377844 * A377846 A377847 A377849

Keyword

nonn,easy

Author

Amiram Eldar, Nov 09 2024

Status

approved