A172991 - cp's OEIS frontend

A172991 Triangle of binomial sums read by rows: T(n,k) = sum(C(2n-2k-i,i) * C(2k-i,i), i=0..min(k,n-k)).

n	a(n)
0	1
1	1
2	1
3	1
4	2
5	1
6	1
7	4
8	4
9	1
10	1
11	6
12	11
13	6
14	1
15	1
16	8
17	22
18	22
19	8
20	1
21	1
22	10
23	37
24	63
25	37
26	10
27	1
28	1
29	12
30	56
31	136
32	136
33	56
34	12
35	1
36	1
37	14
38	79
39	249
40	376
41	249
42	79
43	14
44	1
45	1
46	16
47	106
48	410
49	849
50	849
51	410
52	106
53	16
54	1
55	1
56	18
57	137
58	627
59	1663
60	2317
61	1663
62	627
63	137
64	18
65	1
66	1
67	20
68	172
69	908
70	2942
71	5371
72	5371
73	2942
74	908
75	172
76	20
77	1
78	1
79	22
80	211
81	1261
82	4826
83	11017
84	14545
85	11017
86	4826
87	1261
88	211
89	22
90	1

[1, 1, 1, 1, 2, 1, 1, 4, 4, 1, 1, 6, 11, 6, 1, 1, 8, 22, 22, 8, 1, 1, 10, 37, 63, 37, 10, 1, 1, 12, 56, 136, 136, 56, 12, 1, 1, 14, 79, 249, 376, 249, 79, 14, 1, 1, 16, 106, 410, 849, 849, 410, 106, 16, 1, 1, 18, 137, 627, 1663, 2317, 1663, 627, 137, 18, 1, 1, 20, 172, 908, 2942, 5371, 5371, 2942, 908, 172, 20, 1, 1, 22, 211, 1261, 4826, 11017, 14545, 11017, 4826, 1261, 211, 22, 1]

cp's OEIS Frontend

A172991 Triangle of binomial sums read by rows: T(n,k) = sum(C(2n-2k-i,i) * C(2k-i,i), i=0..min(k,n-k)).

Table of values

List of values