A359371 Nonmultiples of 4 that have an even number of prime factors (with multiplicity).

1, 6, 9, 10, 14, 15, 21, 22, 25, 26, 33, 34, 35, 38, 39, 46, 49, 51, 54, 55, 57, 58, 62, 65, 69, 74, 77, 81, 82, 85, 86, 87, 90, 91, 93, 94, 95, 106, 111, 115, 118, 119, 121, 122, 123, 126, 129, 133, 134, 135, 141, 142, 143, 145, 146, 150, 155, 158, 159, 161, 166, 169, 177, 178, 183, 185, 187, 189

Offset: 1

Author

Antti Karttunen, Dec 28 2022

Keywords

• nonn

Comments

1, and semiprimes other than 4, multiplied by a product of 0 or more odd semiprimes. - Robert Israel, Dec 28 2022

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Intersection of A028260 and A042968.

Setwise difference A042968 \ A359373.

Positions of positive terms in A358839.

Cf. A001222, A008836, A010873, A046337 (subsequence), A166486, A359370 (characteristic function).

Programs

Maple

select(t -> numtheory:-bigomega(t)::even, [seq(seq(4*i+j, j=1..3),i=0..100)]); # Robert Israel, Dec 28 2022

Mathematica

Select[Range[200], And[LiouvilleLambda[#] > 0, ! Divisible[#, 4]] &] (* Michael De Vlieger, Dec 28 2022 *)
Select[Range[200],Mod[#,4]!=0&&EvenQ[PrimeOmega[#]]&] (* Harvey P. Dale, May 20 2025 *)

PARI

isA359371(n) = A359370(n);

Formula

{k | A008836(k) > 0 and A010873(k) > 0}.