A369445 Numerator of sigma(n) / A276086(n), where A276086 is the primorial base exp-function.

1, 1, 2, 7, 1, 12, 4, 1, 13, 2, 2, 28, 7, 8, 4, 31, 1, 39, 2, 14, 16, 4, 4, 12, 31, 14, 4, 56, 1, 72, 16, 3, 8, 6, 8, 13, 19, 4, 4, 2, 1, 96, 22, 4, 13, 8, 8, 124, 57, 31, 12, 14, 3, 24, 36, 8, 8, 2, 2, 24, 31, 32, 52, 127, 2, 144, 34, 6, 16, 16, 4, 39, 37, 38, 62, 4, 16, 24, 8, 62, 121, 2, 2, 32, 54, 44, 4, 4, 1, 234, 8, 8, 64

Offset: 1

Author

Antti Karttunen, Jan 25 2024

Keywords

• nonn
• frac

Links

• Antti Karttunen, Table of n, a(n) for n = 1..16384
• Index entries for sequences related to primorial base
• Index entries for sequences related to sigma(n)

Crossrefs

Cf. A000203, A276086, A324644, A369446 (denominators), A369261.

Programs

PARI

A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
A369445(n) = { my(s=sigma(n)); (s/gcd(s,A276086(n))); };

Formula

a(n) = A000203(n) / A324644(n).