A256116 - cp's OEIS frontend

A256116 Number T(n,k) of length 2n k-ary words, either empty or beginning with the first letter of the alphabet and using each letter at least once, that can be built by repeatedly inserting doublets into the initially empty word; triangle T(n,k), n>=0, 0<=k<=n, read by rows.

n	a(n)
0	1
1	0
2	1
3	0
4	1
5	2
6	0
7	1
8	9
9	10
10	0
11	1
12	34
13	112
14	84
15	0
16	1
17	125
18	930
19	1800
20	1008
21	0
22	1
23	461
24	7018
25	26400
26	35640
27	15840
28	0
29	1
30	1715
31	51142
32	334152
33	816816
34	840840
35	308880
36	0
37	1
38	6434
39	368464
40	3944220
41	15550080
42	27824160
43	23063040
44	7207200

[1, 0, 1, 0, 1, 2, 0, 1, 9, 10, 0, 1, 34, 112, 84, 0, 1, 125, 930, 1800, 1008, 0, 1, 461, 7018, 26400, 35640, 15840, 0, 1, 1715, 51142, 334152, 816816, 840840, 308880, 0, 1, 6434, 368464, 3944220, 15550080, 27824160, 23063040, 7207200]

cp's OEIS Frontend

A256116 Number T(n,k) of length 2n k-ary words, either empty or beginning with the first letter of the alphabet and using each letter at least once, that can be built by repeatedly inserting doublets into the initially empty word; triangle T(n,k), n>=0, 0<=k<=n, read by rows.

Table of values

List of values