A333826 - cp's OEIS frontend

A333826 a(1)=1; for n>1, a(n) = the greatest common divisor (GCD) of n and the sum of all previous terms if the GCD is not already in the sequence; otherwise a(n) = a(n-1) + n.

n	a(n)
1	1
2	3
3	6
4	2
5	7
6	13
7	20
8	4
9	13
10	23
11	34
12	46
13	59
14	73
15	88
16	8
17	25
18	43
19	62
20	10
21	31
22	53
23	76
24	100
25	125
26	151
27	178
28	206
29	235
30	15
31	46
32	78
33	111
34	145
35	5
36	41
37	78
38	116
39	155
40	195
41	236
42	278
43	321
44	365
45	410
46	456
47	503
48	551
49	600
50	50
51	101
52	153
53	206
54	260
55	315
56	371
57	428
58	486
59	545
60	605
61	666
62	728
63	791
64	855
65	920
66	986
67	1053

[1, 3, 6, 2, 7, 13, 20, 4, 13, 23, 34, 46, 59, 73, 88, 8, 25, 43, 62, 10, 31, 53, 76, 100, 125, 151, 178, 206, 235, 15, 46, 78, 111, 145, 5, 41, 78, 116, 155, 195, 236, 278, 321, 365, 410, 456, 503, 551, 600, 50, 101, 153, 206, 260, 315, 371, 428, 486, 545, 605, 666, 728, 791, 855, 920, 986, 1053]

cp's OEIS Frontend

A333826 a(1)=1; for n>1, a(n) = the greatest common divisor (GCD) of n and the sum of all previous terms if the GCD is not already in the sequence; otherwise a(n) = a(n-1) + n.

Table of values

List of values