A136680 - cp's OEIS frontend

A136680 Triangle T(n, k) = f(k) for k < n+1, otherwise 0, where f(k) = f(k-1) + k^(k-2)*f(k-2) with f(0) = 0 and f(1) = 1, read by rows.

n	a(n)
1	1
2	1
3	1
4	1
5	1
6	4
7	1
8	1
9	4
10	20
11	1
12	1
13	4
14	20
15	520
16	1
17	1
18	4
19	20
20	520
21	26440
22	1
23	1
24	4
25	20
26	520
27	26440
28	8766080
29	1
30	1
31	4
32	20
33	520
34	26440
35	8766080
36	6939853440
37	1
38	1
39	4
40	20
41	520
42	26440
43	8766080
44	6939853440
45	41934828744960
46	1
47	1
48	4
49	20
50	520
51	26440
52	8766080
53	6939853440
54	41934828744960
55	694027278828744960

[1, 1, 1, 1, 1, 4, 1, 1, 4, 20, 1, 1, 4, 20, 520, 1, 1, 4, 20, 520, 26440, 1, 1, 4, 20, 520, 26440, 8766080, 1, 1, 4, 20, 520, 26440, 8766080, 6939853440, 1, 1, 4, 20, 520, 26440, 8766080, 6939853440, 41934828744960, 1, 1, 4, 20, 520, 26440, 8766080, 6939853440, 41934828744960, 694027278828744960]

cp's OEIS Frontend

A136680 Triangle T(n, k) = f(k) for k < n+1, otherwise 0, where f(k) = f(k-1) + k^(k-2)*f(k-2) with f(0) = 0 and f(1) = 1, read by rows.

Table of values

List of values