A333440 - cp's OEIS frontend

A333440 Numbers where each digit can be paired with a digit of the same value at another position so that two pairs can be nested but cannot otherwise overlap.

n	a(n)
1	0
2	11
3	22
4	33
5	44
6	55
7	66
8	77
9	88
10	99
11	1001
12	1100
13	1111
14	1122
15	1133
16	1144
17	1155
18	1166
19	1177
20	1188
21	1199
22	1221
23	1331
24	1441
25	1551
26	1661
27	1771
28	1881
29	1991
30	2002
31	2112
32	2200
33	2211
34	2222
35	2233
36	2244
37	2255
38	2266
39	2277
40	2288
41	2299
42	2332
43	2442
44	2552
45	2662
46	2772
47	2882

[0, 11, 22, 33, 44, 55, 66, 77, 88, 99, 1001, 1100, 1111, 1122, 1133, 1144, 1155, 1166, 1177, 1188, 1199, 1221, 1331, 1441, 1551, 1661, 1771, 1881, 1991, 2002, 2112, 2200, 2211, 2222, 2233, 2244, 2255, 2266, 2277, 2288, 2299, 2332, 2442, 2552, 2662, 2772, 2882]

cp's OEIS Frontend

A333440 Numbers where each digit can be paired with a digit of the same value at another position so that two pairs can be nested but cannot otherwise overlap.

Table of values

List of values