A109904 - cp's OEIS frontend

A109904 a(1) = 5. a(n+1) is the greatest prime of the form k*(a(n)-k) + 1. The least prime occurs for k = 1 and a(n+1) = a(n) in that case if no other value of k gives a prime then the sequence terminates.

n	a(n)
1	5
2	7
3	13
4	43
5	463
6	53593
7	718052371
8	128899801874680399
9	4153789730832965126116749598699801
10	4313492281993349218329412357362100514520987205269104143837429352069

[5, 7, 13, 43, 463, 53593, 718052371, 128899801874680399, 4153789730832965126116749598699801, 4313492281993349218329412357362100514520987205269104143837429352069]

cp's OEIS Frontend

A109904 a(1) = 5. a(n+1) is the greatest prime of the form k*(a(n)-k) + 1. The least prime occurs for k = 1 and a(n+1) = a(n) in that case if no other value of k gives a prime then the sequence terminates.

Table of values

List of values