A063384 - cp's OEIS frontend

A063384 a(1) = 7, 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	7
2	17
3	117
4	913
5	1183
6	1391
7	13107
8	51257
9	151257
10	381397
11	577661
12	4911789
13	29116879
14	112646989
15	536920981
16	1928258999
17	11928258999
18	25227472837
19	46275452231
20	212892173679
21	370964057893
22	1859199550327
23	5593332415439

[7, 17, 117, 913, 1183, 1391, 13107, 51257, 151257, 381397, 577661, 4911789, 29116879, 112646989, 536920981, 1928258999, 11928258999, 25227472837, 46275452231, 212892173679, 370964057893, 1859199550327, 5593332415439]

cp's OEIS Frontend

A063384 a(1) = 7, 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