A248971 - cp's OEIS frontend

A248971 Triangular array read by rows. T(n,k)=C(k,2)+C(n-k,2),n>=2,1<=k<=floor(n/2).

n	a(n)
2	0
3	1
4	3
5	2
6	6
7	4
8	10
9	7
10	6
11	15
12	11
13	9
14	21
15	16
16	13
17	12
18	28
19	22
20	18
21	16
22	36
23	29
24	24
25	21
26	20
27	45
28	37
29	31
30	27
31	25
32	55
33	46
34	39
35	34
36	31
37	30
38	66
39	56
40	48
41	42
42	38
43	36
44	78
45	67
46	58
47	51
48	46
49	43
50	42
51	91
52	79
53	69
54	61
55	55
56	51
57	49
58	105
59	92
60	81
61	72
62	65
63	60
64	57
65	56

[0, 1, 3, 2, 6, 4, 10, 7, 6, 15, 11, 9, 21, 16, 13, 12, 28, 22, 18, 16, 36, 29, 24, 21, 20, 45, 37, 31, 27, 25, 55, 46, 39, 34, 31, 30, 66, 56, 48, 42, 38, 36, 78, 67, 58, 51, 46, 43, 42, 91, 79, 69, 61, 55, 51, 49, 105, 92, 81, 72, 65, 60, 57, 56]

cp's OEIS Frontend

A248971 Triangular array read by rows. T(n,k)=C(k,2)+C(n-k,2),n>=2,1<=k<=floor(n/2).

Table of values

List of values

n	a(n)
2	0
3	1
4	3
5	2
6	6
7	4
8	10
9	7
10	6
11	15
12	11
13	9
14	21
15	16
16	13
17	12
18	28
19	22
20	18
21	16
22	36
23	29
24	24
25	21
26	20
27	45
28	37
29	31
30	27
31	25
32	55
33	46
34	39
35	34
36	31
37	30
38	66
39	56
40	48
41	42
42	38
43	36
44	78
45	67
46	58
47	51
48	46
49	43
50	42
51	91
52	79
53	69
54	61
55	55
56	51
57	49
58	105
59	92
60	81
61	72
62	65
63	60
64	57
65	56

n	a(n)
2	0
3	1
4	3
5	2
6	6
7	4
8	10
9	7
10	6
11	15
12	11
13	9
14	21
15	16
16	13
17	12
18	28
19	22
20	18
21	16
22	36
23	29
24	24
25	21
26	20
27	45
28	37
29	31
30	27
31	25
32	55
33	46
34	39
35	34
36	31
37	30
38	66
39	56
40	48
41	42
42	38
43	36
44	78
45	67
46	58
47	51
48	46
49	43
50	42
51	91
52	79
53	69
54	61
55	55
56	51
57	49
58	105
59	92
60	81
61	72
62	65
63	60
64	57
65	56

n	a(n)
2	0
3	1
4	3
5	2
6	6
7	4
8	10
9	7
10	6
11	15
12	11
13	9
14	21
15	16
16	13
17	12
18	28
19	22
20	18
21	16
22	36
23	29
24	24
25	21
26	20
27	45
28	37
29	31
30	27
31	25
32	55
33	46
34	39
35	34
36	31
37	30
38	66
39	56
40	48
41	42
42	38
43	36
44	78
45	67
46	58
47	51
48	46
49	43
50	42
51	91
52	79
53	69
54	61
55	55
56	51
57	49
58	105
59	92
60	81
61	72
62	65
63	60
64	57
65	56