A081465 - cp's OEIS frontend

A081465 Consider the mapping f(a/b) = (a^2+b^2)/(a^2-b^2) from rationals to rationals. Starting with 2/1 (a=2, b=1) and applying the mapping to each new (reduced) rational number gives 2/1, 5/3, 17/8, 353/225, ... . Sequence gives values of the numerators.

n	a(n)
1	2
2	5
3	17
4	353
5	87617
6	9045146753
7	60804857528809666817
8	4138643330264389621194448797227488932353
9	13864359953311401274177801350481278132199085263747363330276605034095638011503617

[2, 5, 17, 353, 87617, 9045146753, 60804857528809666817, 4138643330264389621194448797227488932353, 13864359953311401274177801350481278132199085263747363330276605034095638011503617]

cp's OEIS Frontend

A081465 Consider the mapping f(a/b) = (a^2+b^2)/(a^2-b^2) from rationals to rationals. Starting with 2/1 (a=2, b=1) and applying the mapping to each new (reduced) rational number gives 2/1, 5/3, 17/8, 353/225, ... . Sequence gives values of the numerators.

Table of values

List of values