A339966 a(n) = (n+1) / gcd(sigma(n),n+1).

2, 1, 1, 5, 1, 7, 1, 3, 10, 11, 1, 13, 1, 5, 2, 17, 1, 19, 1, 1, 11, 23, 1, 5, 26, 9, 7, 29, 1, 31, 1, 11, 17, 35, 3, 37, 1, 13, 5, 41, 1, 43, 1, 15, 23, 47, 1, 49, 50, 17, 13, 53, 1, 11, 7, 19, 29, 59, 1, 61, 1, 21, 8, 65, 11, 67, 1, 23, 35, 71, 1, 73, 1, 25, 19, 11, 13, 79, 1, 27, 82, 83, 1, 85, 43, 29, 11, 89, 1, 7

Offset

1,1

Links

Antti Karttunen, Table of n, a(n) for n = 1..65537

Index entries for sequences related to sigma(n)

Formula

a(n) = (n+1) / A339964(n).

a(n) = denominator(sigma(n)/(n+1)). - Michel Marcus, Jan 07 2023

Prog

(PARI) A339966(n) = (n+1)/(gcd(sigma(n), n+1));

Crossrefs

Cf. A000203, A339964, A339965 (numerators).

Cf. A017666.

Cf. also A160596.

Sequence in context: A356399 A136789 A342916 * A347087 A022661 A120292

Adjacent sequences: A339963 A339964 A339965 * A339967 A339968 A339969

Keyword

nonn,frac

Author

Antti Karttunen, Dec 25 2020

Status

approved