A140821 - cp's OEIS frontend

A140821 Coefficients of Hodge diamond GCD binomial product 'X' matrices as polynomials: matrix example; M={{2,0,2}. {0,2,0], {2,0,2}: M(d, x, y)= Sum[Sum[If[n == m, GCD[d - 1, m - 1], If[n == d - m + 1, GCD[d - 1, n - 1], 0]]x^(n - 1)y^(m - 1), {n, 1, d}], {m, 1, d}] .

n	a(n)
1	2
2	2
3	4
4	2
5	4
6	6
7	6
8	6
9	6
10	8
11	8
12	12
13	8
14	8
15	10
16	10
17	20
18	20
19	10
20	10
21	12
22	12
23	60
24	60
25	60
26	12
27	12
28	14
29	14
30	42
31	70
32	70
33	42
34	14
35	14
36	16
37	16
38	112
39	112
40	280
41	112
42	112
43	16
44	16
45	18
46	18
47	72
48	504
49	252
50	252
51	504
52	72
53	18
54	18

[2, 2, 4, 2, 4, 6, 6, 6, 6, 8, 8, 12, 8, 8, 10, 10, 20, 20, 10, 10, 12, 12, 60, 60, 60, 12, 12, 14, 14, 42, 70, 70, 42, 14, 14, 16, 16, 112, 112, 280, 112, 112, 16, 16, 18, 18, 72, 504, 252, 252, 504, 72, 18, 18]

cp's OEIS Frontend

A140821 Coefficients of Hodge diamond GCD binomial product 'X' matrices as polynomials: matrix example; M={{2,0,2}. {0,2,0], {2,0,2}: M(d, x, y)= Sum[Sum[If[n == m, GCD[d - 1, m - 1], If[n == d - m + 1, GCD[d - 1, n - 1], 0]]x^(n - 1)y^(m - 1), {n, 1, d}], {m, 1, d}] .

Table of values

List of values

n	a(n)
1	2
2	2
3	4
4	2
5	4
6	6
7	6
8	6
9	6
10	8
11	8
12	12
13	8
14	8
15	10
16	10
17	20
18	20
19	10
20	10
21	12
22	12
23	60
24	60
25	60
26	12
27	12
28	14
29	14
30	42
31	70
32	70
33	42
34	14
35	14
36	16
37	16
38	112
39	112
40	280
41	112
42	112
43	16
44	16
45	18
46	18
47	72
48	504
49	252
50	252
51	504
52	72
53	18
54	18

n	a(n)
1	2
2	2
3	4
4	2
5	4
6	6
7	6
8	6
9	6
10	8
11	8
12	12
13	8
14	8
15	10
16	10
17	20
18	20
19	10
20	10
21	12
22	12
23	60
24	60
25	60
26	12
27	12
28	14
29	14
30	42
31	70
32	70
33	42
34	14
35	14
36	16
37	16
38	112
39	112
40	280
41	112
42	112
43	16
44	16
45	18
46	18
47	72
48	504
49	252
50	252
51	504
52	72
53	18
54	18

cp's OEIS Frontend

A140821 Coefficients of Hodge diamond GCD binomial product 'X' matrices as polynomials: matrix example; M={{2,0,2}. {0,2,0], {2,0,2}: M(d, x, y)= Sum[Sum[If[n == m, GCD[d - 1, m - 1], If[n == d - m + 1, GCD[d - 1, n - 1], 0]]*x^(n - 1)*y^(m - 1), {n, 1, d}], {m, 1, d}] .

Table of values

List of values

A140821 Coefficients of Hodge diamond GCD binomial product 'X' matrices as polynomials: matrix example; M={{2,0,2}. {0,2,0], {2,0,2}: M(d, x, y)= Sum[Sum[If[n == m, GCD[d - 1, m - 1], If[n == d - m + 1, GCD[d - 1, n - 1], 0]]x^(n - 1)y^(m - 1), {n, 1, d}], {m, 1, d}] .

n	a(n)
1	2
2	2
3	4
4	2
5	4
6	6
7	6
8	6
9	6
10	8
11	8
12	12
13	8
14	8
15	10
16	10
17	20
18	20
19	10
20	10
21	12
22	12
23	60
24	60
25	60
26	12
27	12
28	14
29	14
30	42
31	70
32	70
33	42
34	14
35	14
36	16
37	16
38	112
39	112
40	280
41	112
42	112
43	16
44	16
45	18
46	18
47	72
48	504
49	252
50	252
51	504
52	72
53	18
54	18