A111386 - cp's OEIS frontend

A111386 a(1) = 1, a(2) = 3; for n >= 3, take a(n) to be the smallest odd number not occurring earlier such that a(n-1) divides the concatenation a(n-2)a(n).

n	a(n)
1	1
2	3
3	5
4	15
5	25
6	75
7	125
8	375
9	625
10	1875
11	3125
12	9375
13	15625
14	46875
15	78125
16	234375
17	390625
18	1171875
19	1953125
20	5859375
21	9765625
22	29296875
23	48828125
24	146484375
25	244140625
26	732421875
27	1220703125
28	3662109375
29	6103515625
30	18310546875
31	30517578125

[1, 3, 5, 15, 25, 75, 125, 375, 625, 1875, 3125, 9375, 15625, 46875, 78125, 234375, 390625, 1171875, 1953125, 5859375, 9765625, 29296875, 48828125, 146484375, 244140625, 732421875, 1220703125, 3662109375, 6103515625, 18310546875, 30517578125]

cp's OEIS Frontend

A111386 a(1) = 1, a(2) = 3; for n >= 3, take a(n) to be the smallest odd number not occurring earlier such that a(n-1) divides the concatenation a(n-2)a(n).

Table of values

List of values