A309872 - cp's OEIS frontend

A309872 For each term, take the last digit of the previous term and count all the appearances of that digit up to and including the previous term; the first term is 1.

n	a(n)
1	1
2	1
3	2
4	1
5	3
6	1
7	4
8	1
9	5
10	1
11	6
12	1
13	7
14	1
15	8
16	1
17	9
18	1
19	10
20	1
21	12
22	2
23	3
24	2
25	4
26	2
27	5
28	2
29	6
30	2
31	7
32	2
33	8
34	2
35	9
36	2
37	10
38	2
39	11
40	16
41	3
42	3
43	4
44	3
45	5
46	3
47	6
48	4
49	4
50	5
51	4
52	6
53	5
54	5
55	6
56	6
57	7
58	3
59	7
60	4
61	7
62	5
63	7
64	6
65	8
66	3
67	8
68	4
69	8
70	5
71	8
72	6
73	9
74	3
75	9
76	4
77	9
78	5
79	9
80	6
81	10
82	3
83	10
84	4
85	10
86	5
87	10
88	6
89	11
90	23
91	11

[1, 1, 2, 1, 3, 1, 4, 1, 5, 1, 6, 1, 7, 1, 8, 1, 9, 1, 10, 1, 12, 2, 3, 2, 4, 2, 5, 2, 6, 2, 7, 2, 8, 2, 9, 2, 10, 2, 11, 16, 3, 3, 4, 3, 5, 3, 6, 4, 4, 5, 4, 6, 5, 5, 6, 6, 7, 3, 7, 4, 7, 5, 7, 6, 8, 3, 8, 4, 8, 5, 8, 6, 9, 3, 9, 4, 9, 5, 9, 6, 10, 3, 10, 4, 10, 5, 10, 6, 11, 23, 11]

cp's OEIS Frontend

A309872 For each term, take the last digit of the previous term and count all the appearances of that digit up to and including the previous term; the first term is 1.

Table of values

List of values

n	a(n)
1	1
2	1
3	2
4	1
5	3
6	1
7	4
8	1
9	5
10	1
11	6
12	1
13	7
14	1
15	8
16	1
17	9
18	1
19	10
20	1
21	12
22	2
23	3
24	2
25	4
26	2
27	5
28	2
29	6
30	2
31	7
32	2
33	8
34	2
35	9
36	2
37	10
38	2
39	11
40	16
41	3
42	3
43	4
44	3
45	5
46	3
47	6
48	4
49	4
50	5
51	4
52	6
53	5
54	5
55	6
56	6
57	7
58	3
59	7
60	4
61	7
62	5
63	7
64	6
65	8
66	3
67	8
68	4
69	8
70	5
71	8
72	6
73	9
74	3
75	9
76	4
77	9
78	5
79	9
80	6
81	10
82	3
83	10
84	4
85	10
86	5
87	10
88	6
89	11
90	23
91	11

n	a(n)
1	1
2	1
3	2
4	1
5	3
6	1
7	4
8	1
9	5
10	1
11	6
12	1
13	7
14	1
15	8
16	1
17	9
18	1
19	10
20	1
21	12
22	2
23	3
24	2
25	4
26	2
27	5
28	2
29	6
30	2
31	7
32	2
33	8
34	2
35	9
36	2
37	10
38	2
39	11
40	16
41	3
42	3
43	4
44	3
45	5
46	3
47	6
48	4
49	4
50	5
51	4
52	6
53	5
54	5
55	6
56	6
57	7
58	3
59	7
60	4
61	7
62	5
63	7
64	6
65	8
66	3
67	8
68	4
69	8
70	5
71	8
72	6
73	9
74	3
75	9
76	4
77	9
78	5
79	9
80	6
81	10
82	3
83	10
84	4
85	10
86	5
87	10
88	6
89	11
90	23
91	11

n	a(n)
1	1
2	1
3	2
4	1
5	3
6	1
7	4
8	1
9	5
10	1
11	6
12	1
13	7
14	1
15	8
16	1
17	9
18	1
19	10
20	1
21	12
22	2
23	3
24	2
25	4
26	2
27	5
28	2
29	6
30	2
31	7
32	2
33	8
34	2
35	9
36	2
37	10
38	2
39	11
40	16
41	3
42	3
43	4
44	3
45	5
46	3
47	6
48	4
49	4
50	5
51	4
52	6
53	5
54	5
55	6
56	6
57	7
58	3
59	7
60	4
61	7
62	5
63	7
64	6
65	8
66	3
67	8
68	4
69	8
70	5
71	8
72	6
73	9
74	3
75	9
76	4
77	9
78	5
79	9
80	6
81	10
82	3
83	10
84	4
85	10
86	5
87	10
88	6
89	11
90	23
91	11