A115906 - cp's OEIS frontend

A115906 Numbers k such that k + sigma(k) + phi(k) is a triangular number.

n	a(n)
1	1
2	2
3	5
4	7
5	9
6	16
7	144
8	186
9	410
10	656
11	680
12	805
13	963
14	968
15	1152
16	1331
17	1419
18	1476
19	1557
20	1608
21	2158
22	2220
23	2376
24	2401
25	2529
26	2840
27	3376
28	3447
29	3570
30	3591
31	4018
32	5030
33	5769
34	5967
35	6530
36	6720
37	6854
38	6955
39	7250
40	7856
41	8004
42	8514
43	8946
44	9144

[1, 2, 5, 7, 9, 16, 144, 186, 410, 656, 680, 805, 963, 968, 1152, 1331, 1419, 1476, 1557, 1608, 2158, 2220, 2376, 2401, 2529, 2840, 3376, 3447, 3570, 3591, 4018, 5030, 5769, 5967, 6530, 6720, 6854, 6955, 7250, 7856, 8004, 8514, 8946, 9144]

cp's OEIS Frontend

A115906 Numbers k such that k + sigma(k) + phi(k) is a triangular number.

Table of values

List of values