A027421 - cp's OEIS frontend

A027421 Triangle T(n,k) = number of distinct products i*j with k<=i,j<=n, for 0<=k<=n.

n	a(n)
0	1
1	2
2	1
3	4
4	3
5	1
6	7
7	6
8	3
9	1
10	10
11	9
12	6
13	3
14	1
15	15
16	14
17	10
18	6
19	3
20	1
21	19
22	18
23	14
24	10
25	6
26	3
27	1
28	26
29	25
30	20
31	15
32	10
33	6
34	3
35	1
36	31
37	30
38	25
39	20
40	15
41	10
42	6
43	3
44	1
45	37
46	36
47	31
48	26
49	20
50	15
51	10
52	6
53	3
54	1
55	43
56	42
57	37
58	32
59	26
60	21
61	15
62	10
63	6
64	3
65	1
66	54
67	53
68	47
69	41
70	34
71	28
72	21
73	15
74	10
75	6
76	3
77	1

[1, 2, 1, 4, 3, 1, 7, 6, 3, 1, 10, 9, 6, 3, 1, 15, 14, 10, 6, 3, 1, 19, 18, 14, 10, 6, 3, 1, 26, 25, 20, 15, 10, 6, 3, 1, 31, 30, 25, 20, 15, 10, 6, 3, 1, 37, 36, 31, 26, 20, 15, 10, 6, 3, 1, 43, 42, 37, 32, 26, 21, 15, 10, 6, 3, 1, 54, 53, 47, 41, 34, 28, 21, 15, 10, 6, 3, 1]

cp's OEIS Frontend

A027421 Triangle T(n,k) = number of distinct products i*j with k<=i,j<=n, for 0<=k<=n.

Table of values

List of values

n	a(n)
0	1
1	2
2	1
3	4
4	3
5	1
6	7
7	6
8	3
9	1
10	10
11	9
12	6
13	3
14	1
15	15
16	14
17	10
18	6
19	3
20	1
21	19
22	18
23	14
24	10
25	6
26	3
27	1
28	26
29	25
30	20
31	15
32	10
33	6
34	3
35	1
36	31
37	30
38	25
39	20
40	15
41	10
42	6
43	3
44	1
45	37
46	36
47	31
48	26
49	20
50	15
51	10
52	6
53	3
54	1
55	43
56	42
57	37
58	32
59	26
60	21
61	15
62	10
63	6
64	3
65	1
66	54
67	53
68	47
69	41
70	34
71	28
72	21
73	15
74	10
75	6
76	3
77	1

n	a(n)
0	1
1	2
2	1
3	4
4	3
5	1
6	7
7	6
8	3
9	1
10	10
11	9
12	6
13	3
14	1
15	15
16	14
17	10
18	6
19	3
20	1
21	19
22	18
23	14
24	10
25	6
26	3
27	1
28	26
29	25
30	20
31	15
32	10
33	6
34	3
35	1
36	31
37	30
38	25
39	20
40	15
41	10
42	6
43	3
44	1
45	37
46	36
47	31
48	26
49	20
50	15
51	10
52	6
53	3
54	1
55	43
56	42
57	37
58	32
59	26
60	21
61	15
62	10
63	6
64	3
65	1
66	54
67	53
68	47
69	41
70	34
71	28
72	21
73	15
74	10
75	6
76	3
77	1

n	a(n)
0	1
1	2
2	1
3	4
4	3
5	1
6	7
7	6
8	3
9	1
10	10
11	9
12	6
13	3
14	1
15	15
16	14
17	10
18	6
19	3
20	1
21	19
22	18
23	14
24	10
25	6
26	3
27	1
28	26
29	25
30	20
31	15
32	10
33	6
34	3
35	1
36	31
37	30
38	25
39	20
40	15
41	10
42	6
43	3
44	1
45	37
46	36
47	31
48	26
49	20
50	15
51	10
52	6
53	3
54	1
55	43
56	42
57	37
58	32
59	26
60	21
61	15
62	10
63	6
64	3
65	1
66	54
67	53
68	47
69	41
70	34
71	28
72	21
73	15
74	10
75	6
76	3
77	1