A374047 Numbers k for which A328845(k) is odd, where A328845 is the first Fibonacci based variant of arithmetic derivative.

2, 5, 6, 7, 10, 11, 13, 14, 15, 17, 18, 19, 21, 22, 23, 26, 29, 30, 31, 33, 34, 37, 38, 39, 41, 42, 43, 45, 46, 47, 50, 51, 53, 54, 57, 58, 59, 61, 62, 63, 66, 67, 69, 70, 71, 73, 74, 78, 79, 82, 83, 86, 87, 89, 90, 93, 94, 97, 98, 99, 101, 102, 103, 106, 107, 109, 110, 111, 113, 114, 117, 118, 122, 123, 125, 126, 127

Offset: 1

Author

Antti Karttunen, Jun 27 2024

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..12000

Crossrefs

Cf. A000045, A328845, A374045, A374046 (complement).

Programs

Mathematica

A374047Q[k_] := If[k <= 1, False,OddQ[k*Total[MapApply[#2*Fibonacci[#]/# &, FactorInteger[k]]]]];
Select[Range[0, 200], A374047Q] (* Paolo Xausa, Dec 16 2024 *)

PARI

isA374047(n) = !A374045(n);