A297195 - cp's OEIS frontend

A297195 Number of bitriangular permutations (row sums of A272644 if that triangle is prefixed with two rows for n=0,1).

n	a(n)
0	1
1	0
2	1
3	2
4	7
5	28
6	133
7	726
8	4483
9	30896
10	235105
11	1957930
12	17712799
13	172980804
14	1813760317
15	20323234814
16	242353047355
17	3064550705752
18	40958281206169
19	576917769130578
20	8541793624670551
21	132623408805525740
22	2154730841214003061
23	36560670776303600422
24	646697046042017004787

[1, 0, 1, 2, 7, 28, 133, 726, 4483, 30896, 235105, 1957930, 17712799, 172980804, 1813760317, 20323234814, 242353047355, 3064550705752, 40958281206169, 576917769130578, 8541793624670551, 132623408805525740, 2154730841214003061, 36560670776303600422, 646697046042017004787]

cp's OEIS Frontend

A297195 Number of bitriangular permutations (row sums of A272644 if that triangle is prefixed with two rows for n=0,1).

Table of values

List of values