A371085 Nonsquarefree numbers k such that A003415(k) divides A276086(k), where A003415 is the arithmetic derivative, and A276086 is the primorial base exp-function.

9, 25, 49, 207, 333, 375, 531, 605, 819, 1331, 1719, 1850, 2057, 2205, 2299, 2331, 2853, 4491, 4575, 5746, 6413, 6591, 6655, 9559, 9873, 12947, 13426, 14063, 15851, 15886, 16425, 17303, 19125, 19942, 20531, 21609, 21970, 22139, 26667, 30923, 33975, 34731, 35379, 37251, 37873, 38350, 38599, 39075, 41743, 44447, 45950

Offset: 1

Author

Antti Karttunen, Mar 12 2024

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..7575
• Index entries for sequences related to primorial base

Crossrefs

Intersection of A013929 and A358221 (or A358222).

Subsequence of A371083, and of A371086.

Cf. A003415, A276086.

Programs

PARI

A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
A358220(n) = if(n<2, 0, !(A276086(n)%A003415(n)));
isA371085(n) = (!issquarefree(n)&&A358220(n));