A369003 Numbers k for which k' / gcd(k,k') is odd, where k' stands for the arithmetic derivative of k, A003415.

2, 3, 4, 5, 6, 7, 8, 10, 11, 13, 14, 17, 18, 19, 22, 23, 24, 26, 27, 29, 30, 31, 32, 34, 36, 37, 38, 40, 41, 42, 43, 45, 46, 47, 48, 50, 53, 54, 56, 58, 59, 60, 61, 62, 63, 64, 66, 67, 70, 71, 72, 73, 74, 75, 78, 79, 80, 82, 83, 84, 86, 88, 89, 90, 94, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 109

Offset: 1

Author

Antti Karttunen, Jan 14 2024

Keywords

• nonn

Comments

Numbers k such that A276085(k) is not a multiple of four. - Antti Karttunen, Nov 11 2024

Links

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

Crossrefs

Positions of odd terms in A083345, A373377 and in A373485. Positions of 0's in A369001.

Cf. A003415, A276085, A369002 (complement), A377874 (characteristic function).

Subsequences: A369007, (A377869 U A377875).

Cf. also A368999.

Programs

PARI

isA369003(n) = !A369001(n); \\ See the code in A369001.