A388018 a(n) = A276086(floor(sigma(n)/2)), where A276086 is the primorial base exp-function, and sigma is the sum of divisors function.

1, 2, 3, 6, 6, 5, 9, 10, 5, 30, 5, 75, 10, 25, 25, 150, 30, 250, 45, 750, 225, 125, 25, 7, 150, 750, 375, 5625, 150, 35, 225, 14, 625, 3750, 625, 1050, 250, 7, 5625, 1050, 750, 875, 1125, 175, 210, 35, 625, 147, 5625, 1575, 35, 1750, 3750, 49, 35, 49, 315, 1050, 7, 30625, 14, 875, 7875, 294, 175, 1225, 63, 294

Offset

1,2

Links

Antti Karttunen, Table of n, a(n) for n = 1..11550

Index entries for sequences related to primorial base.

Index entries for sequences related to sigma(n).

Prog

(PARI)
A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
A388018(n) = A276086(floor(sigma(n)/2));

Crossrefs

Cf. A000203, A276086, A388021.

Cf. also A388031.

Sequence in context: A197334 A113399 A085273 * A151850 A290223 A274213

Adjacent sequences: A388015 A388016 A388017 * A388019 A388020 A388021

Keyword

nonn

Author

Antti Karttunen, Sep 16 2025

Status

approved