A359771 Union of even numbers with an odd number of prime factors and odd numbers with an even number of prime factors, when the number of prime factors is counted with multiplicity.

1, 2, 8, 9, 12, 15, 18, 20, 21, 25, 28, 30, 32, 33, 35, 39, 42, 44, 48, 49, 50, 51, 52, 55, 57, 65, 66, 68, 69, 70, 72, 76, 77, 78, 80, 81, 85, 87, 91, 92, 93, 95, 98, 102, 108, 110, 111, 112, 114, 115, 116, 119, 120, 121, 123, 124, 128, 129, 130, 133, 135, 138, 141, 143, 145, 148, 154, 155, 159, 161

Offset

1,2

Links

Table of n, a(n) for n=1..70.

Prog

(PARI) isA359771(n) = A359770(n);

Crossrefs

Union of A046337 and A046470.

Positions of odd terms in A069345.

Cf. A001222, A359770 (characteristic function), A359772 (complement).

Sequence in context: A338807 A020676 A086678 * A289146 A294374 A066550

Adjacent sequences: A359768 A359769 A359770 * A359772 A359773 A359774

Keyword

nonn

Author

Antti Karttunen, Jan 15 2023

Status

approved