A069708 - cp's OEIS frontend

A069708 Triangular numbers with property that swapping first and last digits also gives a triangular number.

n	a(n)
1	1
2	3
3	6
4	10
5	55
6	66
7	120
8	153
9	171
10	190
11	300
12	351
13	595
14	630
15	666
16	820
17	1081
18	1431
19	1711
20	1891
21	3003
22	3403
23	5050
24	5460
25	5565
26	5995
27	6216
28	6786
29	8128
30	8778
31	10011
32	10731
33	11781
34	12561
35	13041
36	13861
37	15051
38	15931
39	16471
40	17020
41	17391
42	17578
43	18721

[1, 3, 6, 10, 55, 66, 120, 153, 171, 190, 300, 351, 595, 630, 666, 820, 1081, 1431, 1711, 1891, 3003, 3403, 5050, 5460, 5565, 5995, 6216, 6786, 8128, 8778, 10011, 10731, 11781, 12561, 13041, 13861, 15051, 15931, 16471, 17020, 17391, 17578, 18721]

cp's OEIS Frontend

A069708 Triangular numbers with property that swapping first and last digits also gives a triangular number.

Table of values

List of values