A069901 - cp's OEIS frontend

A069901 Smallest prime factor of n-th triangular number.

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

[1, 3, 2, 2, 3, 3, 2, 2, 3, 5, 2, 2, 7, 3, 2, 2, 3, 3, 2, 2, 3, 11, 2, 2, 5, 3, 2, 2, 3, 3, 2, 2, 3, 5, 2, 2, 19, 3, 2, 2, 3, 3, 2, 2, 3, 23, 2, 2, 5, 3, 2, 2, 3, 3, 2, 2, 3, 29, 2, 2, 31, 3, 2, 2, 3, 3, 2, 2, 3, 5, 2, 2, 37, 3, 2, 2, 3, 3, 2, 2, 3, 41, 2, 2, 5, 3, 2, 2, 3, 3, 2, 2, 3, 5, 2, 2, 7, 3, 2]

cp's OEIS Frontend

A069901 Smallest prime factor of n-th triangular number.

Table of values

List of values

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

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

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