A063382 - cp's OEIS frontend

A063382 a(1) = 5, a(n) = concatenation of two closest factors of a(n-1) whose product equals a(n-1) or if a(n-1) is a prime then the concatenation of 1 and a(n-1).

n	a(n)
1	5
2	15
3	35
4	57
5	319
6	1129
7	11129
8	31359
9	310453
10	1691837
11	7241691
12	15094799
13	31486929
14	159198031
15	1159198031
16	6203186877
17	11721529237
18	88429132553
19	129487682919
20	1228291054211
21	1394483927247
22	8800411584567
23	34329256355023

[5, 15, 35, 57, 319, 1129, 11129, 31359, 310453, 1691837, 7241691, 15094799, 31486929, 159198031, 1159198031, 6203186877, 11721529237, 88429132553, 129487682919, 1228291054211, 1394483927247, 8800411584567, 34329256355023]

cp's OEIS Frontend

A063382 a(1) = 5, a(n) = concatenation of two closest factors of a(n-1) whose product equals a(n-1) or if a(n-1) is a prime then the concatenation of 1 and a(n-1).

Table of values

List of values