A061915 - cp's OEIS frontend

A061915 Obtain m by omitting trailing zeros from n; a(n) = smallest multiple k*m which is a palindrome with even digits, or -1 if no such multiple exists.

n	a(n)
0	0
1	2
2	2
3	6
4	4
5	-1
6	6
7	686
8	8
9	666
10	2
11	22
12	444
13	2002
14	686
15	-1
16	464
17	646
18	666
19	646
20	2
21	6006
22	22
23	828
24	888
25	-1
26	2002
27	8886888
28	868
29	464
30	6
31	868
32	4224
33	66
34	646
35	-1
36	828
37	222
38	646
39	6006
40	4
41	22222
42	6006
43	68886
44	44
45	-1
46	828
47	282
48	4224
49	686
50	-1
51	42024
52	4004
53	424
54	8886888
55	-1
56	8008
57	68286
58	464
59	68086
60	6

[0, 2, 2, 6, 4, -1, 6, 686, 8, 666, 2, 22, 444, 2002, 686, -1, 464, 646, 666, 646, 2, 6006, 22, 828, 888, -1, 2002, 8886888, 868, 464, 6, 868, 4224, 66, 646, -1, 828, 222, 646, 6006, 4, 22222, 6006, 68886, 44, -1, 828, 282, 4224, 686, -1, 42024, 4004, 424, 8886888, -1, 8008, 68286, 464, 68086, 6]

cp's OEIS Frontend

A061915 Obtain m by omitting trailing zeros from n; a(n) = smallest multiple k*m which is a palindrome with even digits, or -1 if no such multiple exists.

Table of values

List of values