A265009 - cp's OEIS frontend

A265009 a(1)=3; for n>1, if n is odd a(n) = spf(Product_{k=1..n-1}(a(k))+1) else a(n) = spf(Product_{k=1..n-1}(a(k))-1), where spf is "smallest prime factor".

n	a(n)
1	3
2	2
3	7
4	41
5	1723
6	5
7	14835031
8	220078129935929
9	241
10	23
11	79
12	101
13	23291
14	11
15	223
16	122386298896281959929015788890561251765109069
17	38803
18	17
19	8209
20	59
21	199
22	3340389589
23	11527
24	13
25	47939
26	1163
27	599
28	27198087874669514440553
29	181936481
30	31
31	383
32	9623
33	739
34	33287
35	1061
36	6493520653
37	587
38	709
39	6548057
40	1823
41	361789
42	20183

[3, 2, 7, 41, 1723, 5, 14835031, 220078129935929, 241, 23, 79, 101, 23291, 11, 223, 122386298896281959929015788890561251765109069, 38803, 17, 8209, 59, 199, 3340389589, 11527, 13, 47939, 1163, 599, 27198087874669514440553, 181936481, 31, 383, 9623, 739, 33287, 1061, 6493520653, 587, 709, 6548057, 1823, 361789, 20183]

cp's OEIS Frontend

A265009 a(1)=3; for n>1, if n is odd a(n) = spf(Product_{k=1..n-1}(a(k))+1) else a(n) = spf(Product_{k=1..n-1}(a(k))-1), where spf is "smallest prime factor".

Table of values

List of values