A370824 a(n) are the denominators corresponding to A370823(n).

1, 5, 19, 13, 211, 95, 2059, 1261, 19171, 5275, 7613, 1159, 1586131, 4766585, 14316139, 505661, 129009091, 2910965, 1161737179, 12675403, 10458256051, 1364211535, 2002867877, 620687383, 847255055011, 2541798719465, 7625463267259, 157769131169, 68629840493971, 86254737475

Offset

1,2

Comments

See A370823 for more information.

Links

Paolo Xausa, Table of n, a(n) for n = 1..1000

Formula

Denominator of 2^(n-1)*(3^n-1)/(3^n-2^n). - Chai Wah Wu, Mar 07 2024

Example

A370823(n)/a(n) for n = 1..11: 2/1, 16/5, 104/19, 128/13, 3872/211, 3328/95, 139904/2059, 167936/1261, 5038592/19171, 2748416/5275, 7886848/7613.

Mathematica

Array[Denominator[(3^#-1)/((3/2)^#-1)/2] &, 35] (* Paolo Xausa, Mar 13 2024 *)

Prog

(PARI) \\ See A370823 for functions a370823_4(n)
denominator(a370823_4(n))
(Python)
from math import gcd
def A370824(n): return (a:=3**n-(1<<n))//gcd(a, 3**n-1<<n-1) # Chai Wah Wu, Mar 07 2024

Crossrefs

A370823 are the corresponding numerators.

Sequence in context: A106229 A129734 A109325 * A169698 A211177 A260645

Adjacent sequences: A370821 A370822 A370823 * A370825 A370826 A370827

Keyword

nonn,frac

Author

Hugo Pfoertner, Mar 02 2024

Status

approved