A075024 - cp's OEIS frontend

A075024 a(n) is the largest prime divisor of the number A173426(n) = concatenate(1,2,...,n-1,n,n-1,...,2,1); a(1) = 1.

n	a(n)
1	1
2	11
3	37
4	101
5	271
6	37
7	4649
8	137
9	333667
10	12345678910987654321
11	17636684157301569664903
12	2799473675762179389994681
13	2354041513534224607850261
14	2068140300159522133
15	498056174529497
16	112240064764214229701
17	4188353169004802474320231191377

[1, 11, 37, 101, 271, 37, 4649, 137, 333667, 12345678910987654321, 17636684157301569664903, 2799473675762179389994681, 2354041513534224607850261, 2068140300159522133, 498056174529497, 112240064764214229701, 4188353169004802474320231191377]

cp's OEIS Frontend

A075024 a(n) is the largest prime divisor of the number A173426(n) = concatenate(1,2,...,n-1,n,n-1,...,2,1); a(1) = 1.

Table of values

List of values