A331762 - cp's OEIS frontend

A331762 Triangle read by rows: T(n,k) (1 <= k <= n) = Sum_{i=1..n, j=1..k, gcd(i,j)=2} (n+1-i)*(k+1-j).

n	a(n)
1	0
2	0
3	1
4	0
5	2
6	4
7	0
8	4
9	8
10	15
11	0
12	6
13	12
14	22
15	32
16	0
17	9
18	18
19	33
20	48
21	71
22	0
23	12
24	24
25	44
26	64
27	94
28	124
29	0
30	16
31	32
32	58
33	84
34	123
35	162
36	211
37	0
38	20
39	40
40	72
41	104
42	152
43	200
44	260
45	320
46	0
47	25
48	50
49	90
50	130
51	190
52	250
53	325
54	400
55	499

[0, 0, 1, 0, 2, 4, 0, 4, 8, 15, 0, 6, 12, 22, 32, 0, 9, 18, 33, 48, 71, 0, 12, 24, 44, 64, 94, 124, 0, 16, 32, 58, 84, 123, 162, 211, 0, 20, 40, 72, 104, 152, 200, 260, 320, 0, 25, 50, 90, 130, 190, 250, 325, 400, 499]

cp's OEIS Frontend

A331762 Triangle read by rows: T(n,k) (1 <= k <= n) = Sum_{i=1..n, j=1..k, gcd(i,j)=2} (n+1-i)*(k+1-j).

Table of values

List of values

n	a(n)
1	0
2	0
3	1
4	0
5	2
6	4
7	0
8	4
9	8
10	15
11	0
12	6
13	12
14	22
15	32
16	0
17	9
18	18
19	33
20	48
21	71
22	0
23	12
24	24
25	44
26	64
27	94
28	124
29	0
30	16
31	32
32	58
33	84
34	123
35	162
36	211
37	0
38	20
39	40
40	72
41	104
42	152
43	200
44	260
45	320
46	0
47	25
48	50
49	90
50	130
51	190
52	250
53	325
54	400
55	499

n	a(n)
1	0
2	0
3	1
4	0
5	2
6	4
7	0
8	4
9	8
10	15
11	0
12	6
13	12
14	22
15	32
16	0
17	9
18	18
19	33
20	48
21	71
22	0
23	12
24	24
25	44
26	64
27	94
28	124
29	0
30	16
31	32
32	58
33	84
34	123
35	162
36	211
37	0
38	20
39	40
40	72
41	104
42	152
43	200
44	260
45	320
46	0
47	25
48	50
49	90
50	130
51	190
52	250
53	325
54	400
55	499

n	a(n)
1	0
2	0
3	1
4	0
5	2
6	4
7	0
8	4
9	8
10	15
11	0
12	6
13	12
14	22
15	32
16	0
17	9
18	18
19	33
20	48
21	71
22	0
23	12
24	24
25	44
26	64
27	94
28	124
29	0
30	16
31	32
32	58
33	84
34	123
35	162
36	211
37	0
38	20
39	40
40	72
41	104
42	152
43	200
44	260
45	320
46	0
47	25
48	50
49	90
50	130
51	190
52	250
53	325
54	400
55	499