A027751 - cp's OEIS frontend

A027751 Irregular triangle read by rows in which row n lists the proper divisors of n (those divisors of n which are < n), with the first row {1} by convention.

n	a(n)
1	1
2	1
3	1
4	1
5	2
6	1
7	1
8	2
9	3
10	1
11	1
12	2
13	4
14	1
15	3
16	1
17	2
18	5
19	1
20	1
21	2
22	3
23	4
24	6
25	1
26	1
27	2
28	7
29	1
30	3
31	5
32	1
33	2
34	4
35	8
36	1
37	1
38	2
39	3
40	6
41	9
42	1
43	1
44	2
45	4
46	5
47	10
48	1
49	3
50	7
51	1
52	2
53	11
54	1
55	1
56	2
57	3
58	4
59	6
60	8
61	12
62	1
63	5
64	1
65	2
66	13
67	1
68	3
69	9
70	1
71	2
72	4
73	7
74	14
75	1
76	1
77	2
78	3
79	5
80	6
81	10
82	15
83	1
84	1
85	2
86	4
87	8
88	16
89	1
90	3
91	11
92	1
93	2
94	17
95	1
96	5
97	7
98	1
99	2
100	3
101	4
102	6
103	9
104	12
105	18

[1, 1, 1, 1, 2, 1, 1, 2, 3, 1, 1, 2, 4, 1, 3, 1, 2, 5, 1, 1, 2, 3, 4, 6, 1, 1, 2, 7, 1, 3, 5, 1, 2, 4, 8, 1, 1, 2, 3, 6, 9, 1, 1, 2, 4, 5, 10, 1, 3, 7, 1, 2, 11, 1, 1, 2, 3, 4, 6, 8, 12, 1, 5, 1, 2, 13, 1, 3, 9, 1, 2, 4, 7, 14, 1, 1, 2, 3, 5, 6, 10, 15, 1, 1, 2, 4, 8, 16, 1, 3, 11, 1, 2, 17, 1, 5, 7, 1, 2, 3, 4, 6, 9, 12, 18]

cp's OEIS Frontend

A027751 Irregular triangle read by rows in which row n lists the proper divisors of n (those divisors of n which are < n), with the first row {1} by convention.

Table of values

List of values

n	a(n)
1	1
2	1
3	1
4	1
5	2
6	1
7	1
8	2
9	3
10	1
11	1
12	2
13	4
14	1
15	3
16	1
17	2
18	5
19	1
20	1
21	2
22	3
23	4
24	6
25	1
26	1
27	2
28	7
29	1
30	3
31	5
32	1
33	2
34	4
35	8
36	1
37	1
38	2
39	3
40	6
41	9
42	1
43	1
44	2
45	4
46	5
47	10
48	1
49	3
50	7
51	1
52	2
53	11
54	1
55	1
56	2
57	3
58	4
59	6
60	8
61	12
62	1
63	5
64	1
65	2
66	13
67	1
68	3
69	9
70	1
71	2
72	4
73	7
74	14
75	1
76	1
77	2
78	3
79	5
80	6
81	10
82	15
83	1
84	1
85	2
86	4
87	8
88	16
89	1
90	3
91	11
92	1
93	2
94	17
95	1
96	5
97	7
98	1
99	2
100	3
101	4
102	6
103	9
104	12
105	18

n	a(n)
1	1
2	1
3	1
4	1
5	2
6	1
7	1
8	2
9	3
10	1
11	1
12	2
13	4
14	1
15	3
16	1
17	2
18	5
19	1
20	1
21	2
22	3
23	4
24	6
25	1
26	1
27	2
28	7
29	1
30	3
31	5
32	1
33	2
34	4
35	8
36	1
37	1
38	2
39	3
40	6
41	9
42	1
43	1
44	2
45	4
46	5
47	10
48	1
49	3
50	7
51	1
52	2
53	11
54	1
55	1
56	2
57	3
58	4
59	6
60	8
61	12
62	1
63	5
64	1
65	2
66	13
67	1
68	3
69	9
70	1
71	2
72	4
73	7
74	14
75	1
76	1
77	2
78	3
79	5
80	6
81	10
82	15
83	1
84	1
85	2
86	4
87	8
88	16
89	1
90	3
91	11
92	1
93	2
94	17
95	1
96	5
97	7
98	1
99	2
100	3
101	4
102	6
103	9
104	12
105	18

n	a(n)
1	1
2	1
3	1
4	1
5	2
6	1
7	1
8	2
9	3
10	1
11	1
12	2
13	4
14	1
15	3
16	1
17	2
18	5
19	1
20	1
21	2
22	3
23	4
24	6
25	1
26	1
27	2
28	7
29	1
30	3
31	5
32	1
33	2
34	4
35	8
36	1
37	1
38	2
39	3
40	6
41	9
42	1
43	1
44	2
45	4
46	5
47	10
48	1
49	3
50	7
51	1
52	2
53	11
54	1
55	1
56	2
57	3
58	4
59	6
60	8
61	12
62	1
63	5
64	1
65	2
66	13
67	1
68	3
69	9
70	1
71	2
72	4
73	7
74	14
75	1
76	1
77	2
78	3
79	5
80	6
81	10
82	15
83	1
84	1
85	2
86	4
87	8
88	16
89	1
90	3
91	11
92	1
93	2
94	17
95	1
96	5
97	7
98	1
99	2
100	3
101	4
102	6
103	9
104	12
105	18