A213517 - cp's OEIS frontend

A213517 Numbers n such that the triangular number n*(n+1)/2 has only 1 or 2 different digits in base 10.

n	a(n)
1	0
2	1
3	2
4	3
5	4
6	5
7	6
8	7
9	8
10	9
11	10
12	11
13	12
14	13
15	18
16	24
17	34
18	36
19	44
20	58
21	66
22	77
23	100
24	101
25	105
26	109
27	114
28	132
29	141
30	363
31	666
32	714
33	816
34	1000
35	1095
36	1287
37	1332
38	1541
39	3363
40	6666
41	10000
42	10114
43	13332
44	66666
45	100000
46	133332
47	666666
48	1000000
49	1333332
50	6666666
51	10000000

[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 18, 24, 34, 36, 44, 58, 66, 77, 100, 101, 105, 109, 114, 132, 141, 363, 666, 714, 816, 1000, 1095, 1287, 1332, 1541, 3363, 6666, 10000, 10114, 13332, 66666, 100000, 133332, 666666, 1000000, 1333332, 6666666, 10000000]

cp's OEIS Frontend

A213517 Numbers n such that the triangular number n*(n+1)/2 has only 1 or 2 different digits in base 10.

Table of values

List of values