A339403 - cp's OEIS frontend

A339403 a(n) is the smallest positive integer such that n*a(n) contains the string n+a(n) in reverse as a substring. If no such number exists then a(n) = -1.

n	a(n)
0	0
1	-1
2	2
3	24
4	37
5	26
6	34
7	35
8	57
9	9
10	-1
11	12
12	11
13	45
14	193
15	228
16	28
17	51
18	23
19	44
20	841
21	11
22	27
23	18
24	3
25	626
26	5
27	22
28	16
29	46716
30	56
31	41
32	33
33	32
34	6
35	7
36	21
37	4
38	3
39	24
40	592
41	31
42	7
43	619
44	19
45	13
46	38
47	2
48	117
49	5
50	463
51	17
52	34
53	308
54	33
55	36
56	30
57	8
58	31
59	4
60	23
61	21
62	648
63	124
64	921
65	903
66	386
67	395
68	4
69	334
70	755
71	31
72	563

[0, -1, 2, 24, 37, 26, 34, 35, 57, 9, -1, 12, 11, 45, 193, 228, 28, 51, 23, 44, 841, 11, 27, 18, 3, 626, 5, 22, 16, 46716, 56, 41, 33, 32, 6, 7, 21, 4, 3, 24, 592, 31, 7, 619, 19, 13, 38, 2, 117, 5, 463, 17, 34, 308, 33, 36, 30, 8, 31, 4, 23, 21, 648, 124, 921, 903, 386, 395, 4, 334, 755, 31, 563]

cp's OEIS Frontend

A339403 a(n) is the smallest positive integer such that n*a(n) contains the string n+a(n) in reverse as a substring. If no such number exists then a(n) = -1.

Table of values

List of values