A372621 - cp's OEIS frontend

A372621 a(n) = (1/2) * Sum_{k=1..n} phi(3*k).

n	a(n)
1	1
2	2
3	5
4	7
5	11
6	14
7	20
8	24
9	33
10	37
11	47
12	53
13	65
14	71
15	83
16	91
17	107
18	116
19	134
20	142
21	160
22	170
23	192
24	204
25	224
26	236
27	263
28	275
29	303
30	315
31	345
32	361
33	391
34	407
35	431
36	449
37	485
38	503
39	539
40	555
41	595
42	613
43	655
44	675
45	711
46	733
47	779
48	803
49	845
50	865
51	913
52	937
53	989
54	1016
55	1056
56	1080
57	1134

[1, 2, 5, 7, 11, 14, 20, 24, 33, 37, 47, 53, 65, 71, 83, 91, 107, 116, 134, 142, 160, 170, 192, 204, 224, 236, 263, 275, 303, 315, 345, 361, 391, 407, 431, 449, 485, 503, 539, 555, 595, 613, 655, 675, 711, 733, 779, 803, 845, 865, 913, 937, 989, 1016, 1056, 1080, 1134]

cp's OEIS Frontend

A372621 a(n) = (1/2) * Sum_{k=1..n} phi(3*k).

Table of values

List of values