A368999 Numbers k for which A342001(k) is odd.

2, 3, 5, 6, 7, 8, 10, 11, 13, 14, 17, 18, 19, 22, 23, 24, 26, 27, 29, 30, 31, 32, 34, 37, 38, 40, 41, 42, 43, 45, 46, 47, 50, 53, 54, 56, 58, 59, 61, 62, 63, 66, 67, 70, 71, 72, 73, 74, 75, 78, 79, 82, 83, 86, 88, 89, 90, 94, 96, 97, 98, 99, 101, 102, 103, 104, 105, 106, 107, 109, 110, 113, 114, 117, 118, 120, 122, 125

Offset: 1

Author

Antti Karttunen, Jan 14 2024

Keywords

• nonn

Crossrefs

Cf. A342001.

Positions of 0's in A368997. Cf. A368999 (complement).

Programs

PARI

A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
A003557(n) = (n/factorback(factorint(n)[, 1]));
A342001(n) = (A003415(n) / A003557(n));
isA368999(n) = (A342001(n)%2);