A115905 - cp's OEIS frontend

A115905 Numbers k such that k + phi(k) is a triangular number.

n	a(n)
1	2
2	4
3	9
4	11
5	20
6	23
7	25
8	27
9	49
10	53
11	92
12	93
13	105
14	121
15	127
16	147
17	150
18	163
19	169
20	220
21	228
22	231
23	233
24	281
25	286
26	289
27	294
28	332
29	361
30	431
31	474
32	529
33	541
34	543
35	548
36	613
37	660
38	675
39	710
40	726
41	743
42	825
43	827
44	841
45	888
46	891
47	961
48	977
49	993
50	1014
51	1028
52	1265
53	1310
54	1369

[2, 4, 9, 11, 20, 23, 25, 27, 49, 53, 92, 93, 105, 121, 127, 147, 150, 163, 169, 220, 228, 231, 233, 281, 286, 289, 294, 332, 361, 431, 474, 529, 541, 543, 548, 613, 660, 675, 710, 726, 743, 825, 827, 841, 888, 891, 961, 977, 993, 1014, 1028, 1265, 1310, 1369]

cp's OEIS Frontend

A115905 Numbers k such that k + phi(k) is a triangular number.

Table of values

List of values