A054120 - cp's OEIS frontend

A054120 Triangular array T(n,k): start with T(n,0)=T(n,n)=1 for n >= 0; recursively, draw vertical lines through T(n-1,k-1) if present and T(n-1,k) if present; then T(n,k) is the sum of T(i,j) that lie on or between the lines and not below T(n,k).

n	a(n)
0	1
1	1
2	1
3	1
4	3
5	1
6	1
7	6
8	6
9	1
10	1
11	9
12	18
13	9
14	1
15	1
16	12
17	39
18	39
19	12
20	1
21	1
22	15
23	69
24	114
25	69
26	15
27	1
28	1
29	18
30	108
31	261
32	261
33	108
34	18
35	1
36	1
37	21
38	156
39	507
40	750
41	507
42	156
43	21
44	1
45	1
46	24
47	213
48	879
49	1779
50	1779
51	879
52	213
53	24
54	1
55	1
56	27
57	279
58	1404
59	3672
60	5058

[1, 1, 1, 1, 3, 1, 1, 6, 6, 1, 1, 9, 18, 9, 1, 1, 12, 39, 39, 12, 1, 1, 15, 69, 114, 69, 15, 1, 1, 18, 108, 261, 261, 108, 18, 1, 1, 21, 156, 507, 750, 507, 156, 21, 1, 1, 24, 213, 879, 1779, 1779, 879, 213, 24, 1, 1, 27, 279, 1404, 3672, 5058]

cp's OEIS Frontend

A054120 Triangular array T(n,k): start with T(n,0)=T(n,n)=1 for n >= 0; recursively, draw vertical lines through T(n-1,k-1) if present and T(n-1,k) if present; then T(n,k) is the sum of T(i,j) that lie on or between the lines and not below T(n,k).

Table of values

List of values