A340779 - cp's OEIS frontend

A340779 a(1)=1, a(2)=2; for n>=3, a(n) = the closest number to a(n-1) that has not occurred earlier and has at least one common factor with a(n-1), but none with a(n-2). In case of a tie, choose the smaller.

n	a(n)
1	1
2	2
3	6
4	15
5	35
6	28
7	26
8	39
9	33
10	22
11	20
12	45
13	51
14	34
15	38
16	57
17	63
18	56
19	58
20	87
21	93
22	62
23	68
24	85
25	75
26	72
27	74
28	185
29	175
30	168
31	166
32	415
33	405
34	402
35	404
36	505
37	495
38	492
39	494
40	481
41	407
42	396
43	394
44	985
45	975
46	972
47	974
48	2435
49	2425
50	2328
51	2326
52	5815
53	5805
54	5802
55	5804
56	7255
57	7245
58	7242
59	7244
60	9055

[1, 2, 6, 15, 35, 28, 26, 39, 33, 22, 20, 45, 51, 34, 38, 57, 63, 56, 58, 87, 93, 62, 68, 85, 75, 72, 74, 185, 175, 168, 166, 415, 405, 402, 404, 505, 495, 492, 494, 481, 407, 396, 394, 985, 975, 972, 974, 2435, 2425, 2328, 2326, 5815, 5805, 5802, 5804, 7255, 7245, 7242, 7244, 9055]

cp's OEIS Frontend

A340779 a(1)=1, a(2)=2; for n>=3, a(n) = the closest number to a(n-1) that has not occurred earlier and has at least one common factor with a(n-1), but none with a(n-2). In case of a tie, choose the smaller.

Table of values

List of values