A341130 - cp's OEIS frontend

A341130 a(n) = abs(a(n-1) - a(n-2)) if a(n-1) and a(n-2) are both prime or both composite. a(n) = a(n-1) + a(n-2) otherwise, where a(1) = 1 and a(2) = 2 and n > 2.

n	a(n)
1	1
2	2
3	3
4	1
5	4
6	5
7	9
8	14
9	5
10	19
11	14
12	33
13	19
14	52
15	71
16	123
17	194
18	71
19	265
20	336
21	71
22	407
23	478
24	71
25	549
26	620
27	71
28	691
29	620
30	1311
31	691
32	2002
33	2693
34	4695
35	7388
36	2693
37	10081
38	12774
39	2693
40	15467
41	12774
42	28241
43	15467
44	43708
45	59175
46	15467
47	74642
48	90109
49	15467
50	105576
51	121043

[1, 2, 3, 1, 4, 5, 9, 14, 5, 19, 14, 33, 19, 52, 71, 123, 194, 71, 265, 336, 71, 407, 478, 71, 549, 620, 71, 691, 620, 1311, 691, 2002, 2693, 4695, 7388, 2693, 10081, 12774, 2693, 15467, 12774, 28241, 15467, 43708, 59175, 15467, 74642, 90109, 15467, 105576, 121043]

cp's OEIS Frontend

A341130 a(n) = abs(a(n-1) - a(n-2)) if a(n-1) and a(n-2) are both prime or both composite. a(n) = a(n-1) + a(n-2) otherwise, where a(1) = 1 and a(2) = 2 and n > 2.

Table of values

List of values