A074836 - cp's OEIS frontend

A074836 a(1) = 1, a(n) = the largest prime divisor of concatenation of sequence (n,n-1,..,2,1,2,..,n-1,n) A007942.

n	a(n)
1	1
2	53
3	353
4	2160617
5	479
6	146053847
7	18533465459
8	18588601
9	444444443
10	10987654321234567891
11	41824630287288128897
12	24899126702236725259
13	131211109876543212345678910111213
14	59722151033999393
15	1081735780698166140181
16	40378532802777469135803086419727527803285379

[1, 53, 353, 2160617, 479, 146053847, 18533465459, 18588601, 444444443, 10987654321234567891, 41824630287288128897, 24899126702236725259, 131211109876543212345678910111213, 59722151033999393, 1081735780698166140181, 40378532802777469135803086419727527803285379]

cp's OEIS Frontend

A074836 a(1) = 1, a(n) = the largest prime divisor of concatenation of sequence (n,n-1,..,2,1,2,..,n-1,n) A007942.

Table of values

List of values