A165999 - cp's OEIS frontend

A165999 Triangle read by rows: T(0,0) = 1, T(n,k) = T(n-1,k-1) + T(n-1,k) for n > 0, 0 < k <= trinv(n), where trinv(n) = floor((1+sqrt(1+8*n))/2), and entries outside triangle are 0.

n	a(n)
0	1
1	1
2	1
3	1
4	2
5	1
6	3
7	2
8	1
9	4
10	5
11	1
12	5
13	9
14	1
15	6
16	14
17	9
18	1
19	7
20	20
21	23
22	1
23	8
24	27
25	43
26	1
27	9
28	35
29	70
30	1
31	10
32	44
33	105
34	70
35	1
36	11
37	54
38	149
39	175
40	1
41	12
42	65
43	203
44	324
45	1
46	13
47	77
48	268
49	527
50	1
51	14
52	90
53	345
54	795
55	1
56	15
57	104
58	435
59	1140
60	795
61	1
62	16
63	119
64	539
65	1575
66	1935
67	1
68	17
69	135
70	658
71	2114

[1, 1, 1, 1, 2, 1, 3, 2, 1, 4, 5, 1, 5, 9, 1, 6, 14, 9, 1, 7, 20, 23, 1, 8, 27, 43, 1, 9, 35, 70, 1, 10, 44, 105, 70, 1, 11, 54, 149, 175, 1, 12, 65, 203, 324, 1, 13, 77, 268, 527, 1, 14, 90, 345, 795, 1, 15, 104, 435, 1140, 795, 1, 16, 119, 539, 1575, 1935, 1, 17, 135, 658, 2114]

cp's OEIS Frontend

A165999 Triangle read by rows: T(0,0) = 1, T(n,k) = T(n-1,k-1) + T(n-1,k) for n > 0, 0 < k <= trinv(n), where trinv(n) = floor((1+sqrt(1+8*n))/2), and entries outside triangle are 0.

Table of values

List of values