A373375 Numbers whose sum of prime factors (with repetition, A001414) and arithmetic derivative (A003415) are both even.

1, 4, 8, 9, 15, 16, 21, 25, 32, 33, 35, 36, 39, 49, 51, 55, 57, 60, 64, 65, 69, 72, 77, 81, 84, 85, 87, 91, 93, 95, 100, 111, 115, 119, 120, 121, 123, 128, 129, 132, 133, 135, 140, 141, 143, 144, 145, 155, 156, 159, 161, 168, 169, 177, 183, 185, 187, 189, 196, 200, 201, 203, 204, 205, 209, 213, 215, 217, 219, 220, 221

Offset: 1

Author

Antti Karttunen, Jun 03 2024

Keywords

• nonn

Comments

Numbers k such that sopfr(k) and k' are both even.

A multiplicative semigroup; if m and n are in the sequence then so is m*n.

Links

• Antti Karttunen, Table of n, a(n) for n = 1..10000

Crossrefs

Intersection of A036349 and A235992.

Disjoint union of A345452 and 8*A345452.

Positions of even terms in A373364.

Cf. A001414, A003415, A373374 (characteristic function), A373376 (complement).

Programs

PARI

isA373375 = A373374;