A140818 - cp's OEIS frontend

A140818 Coefficients of Hodge diamond binomial 'X' matrices as polynomials: matrix example; M={{1,0,1}. {0,2,0], {1,0,1}: M(d, x, y)= Sum[Sum[If[n == m, Binomial[d - 1, m - 1], If[n == d - m + 1, Binomial[d - 1, n - 1], 0]]x^(n - 1)y^(m - 1), {n, 1, d}], {m, 1, d}] .

n	a(n)
1	1
2	2
3	2
4	2
5	2
6	2
7	2
8	6
9	6
10	2
11	2
12	8
13	6
14	8
15	2
16	2
17	10
18	20
19	20
20	10
21	2
22	2
23	12
24	30
25	20
26	30
27	12
28	2
29	2
30	14
31	42
32	70
33	70
34	42
35	14
36	2
37	2
38	16
39	56
40	112
41	70
42	112
43	56
44	16
45	2
46	2
47	18
48	72
49	168
50	252
51	252
52	168
53	72
54	18
55	2

[1, 2, 2, 2, 2, 2, 2, 6, 6, 2, 2, 8, 6, 8, 2, 2, 10, 20, 20, 10, 2, 2, 12, 30, 20, 30, 12, 2, 2, 14, 42, 70, 70, 42, 14, 2, 2, 16, 56, 112, 70, 112, 56, 16, 2, 2, 18, 72, 168, 252, 252, 168, 72, 18, 2]

cp's OEIS Frontend

A140818 Coefficients of Hodge diamond binomial 'X' matrices as polynomials: matrix example; M={{1,0,1}. {0,2,0], {1,0,1}: M(d, x, y)= Sum[Sum[If[n == m, Binomial[d - 1, m - 1], If[n == d - m + 1, Binomial[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	1
2	2
3	2
4	2
5	2
6	2
7	2
8	6
9	6
10	2
11	2
12	8
13	6
14	8
15	2
16	2
17	10
18	20
19	20
20	10
21	2
22	2
23	12
24	30
25	20
26	30
27	12
28	2
29	2
30	14
31	42
32	70
33	70
34	42
35	14
36	2
37	2
38	16
39	56
40	112
41	70
42	112
43	56
44	16
45	2
46	2
47	18
48	72
49	168
50	252
51	252
52	168
53	72
54	18
55	2

n	a(n)
1	1
2	2
3	2
4	2
5	2
6	2
7	2
8	6
9	6
10	2
11	2
12	8
13	6
14	8
15	2
16	2
17	10
18	20
19	20
20	10
21	2
22	2
23	12
24	30
25	20
26	30
27	12
28	2
29	2
30	14
31	42
32	70
33	70
34	42
35	14
36	2
37	2
38	16
39	56
40	112
41	70
42	112
43	56
44	16
45	2
46	2
47	18
48	72
49	168
50	252
51	252
52	168
53	72
54	18
55	2

cp's OEIS Frontend

A140818 Coefficients of Hodge diamond binomial 'X' matrices as polynomials: matrix example; M={{1,0,1}. {0,2,0], {1,0,1}: M(d, x, y)= Sum[Sum[If[n == m, Binomial[d - 1, m - 1], If[n == d - m + 1, Binomial[d - 1, n - 1], 0]]*x^(n - 1)*y^(m - 1), {n, 1, d}], {m, 1, d}] .

Table of values

List of values

A140818 Coefficients of Hodge diamond binomial 'X' matrices as polynomials: matrix example; M={{1,0,1}. {0,2,0], {1,0,1}: M(d, x, y)= Sum[Sum[If[n == m, Binomial[d - 1, m - 1], If[n == d - m + 1, Binomial[d - 1, n - 1], 0]]x^(n - 1)y^(m - 1), {n, 1, d}], {m, 1, d}] .

n	a(n)
1	1
2	2
3	2
4	2
5	2
6	2
7	2
8	6
9	6
10	2
11	2
12	8
13	6
14	8
15	2
16	2
17	10
18	20
19	20
20	10
21	2
22	2
23	12
24	30
25	20
26	30
27	12
28	2
29	2
30	14
31	42
32	70
33	70
34	42
35	14
36	2
37	2
38	16
39	56
40	112
41	70
42	112
43	56
44	16
45	2
46	2
47	18
48	72
49	168
50	252
51	252
52	168
53	72
54	18
55	2