A087473 - cp's OEIS frontend

A087473 Smallest positive number that requires n iterations of f(k) to reach a single digit, where f(k) is the product of the two numbers formed from the alternating digits of k.

n	a(n)
0	1
1	10
2	25
3	39
4	77
5	171
6	199
7	577
8	887
9	1592
10	2682
11	3988
12	6913
13	18747
14	39577
15	58439
16	99428
17	173442
18	267343
19	299137
20	574182
21	685812
22	880543
23	1635812
24	1974447
25	2771717
26	18871813
27	45797337
28	49899368
29	58935768
30	158504329
31	265956179
32	566800111
33	896125563

[1, 10, 25, 39, 77, 171, 199, 577, 887, 1592, 2682, 3988, 6913, 18747, 39577, 58439, 99428, 173442, 267343, 299137, 574182, 685812, 880543, 1635812, 1974447, 2771717, 18871813, 45797337, 49899368, 58935768, 158504329, 265956179, 566800111, 896125563]

cp's OEIS Frontend

A087473 Smallest positive number that requires n iterations of f(k) to reach a single digit, where f(k) is the product of the two numbers formed from the alternating digits of k.

Table of values

List of values