A287021 - cp's OEIS frontend

A287021 Triangle read by rows: T(n,m) is the number of inequivalent n X m matrices under action of the Klein group, with one-fifth of 1s, 2s, 3s, 4s and 5s (ordered occurrences rounded up/down if n*m != 0 mod 5).

n	a(n)
0	1
1	1
2	1
3	1
4	1
5	1
6	1
7	1
8	90
9	5712
10	1
11	1
12	1260
13	416064
14	168168000
15	1
16	60
17	28440
18	42045600
19	76385194200
20	155840192585280
21	1
22	180
23	415800
24	3216282300
25	31168037156256
26	342718542439257600
27	3574641463338838464000
28	1
29	630
30	8408400
31	320818773240
32	14181456923282880
33	794364769671213312000
34	40694019408428534970822000
35	2416738787895064029335795945088

[1, 1, 1, 1, 1, 1, 1, 1, 90, 5712, 1, 1, 1260, 416064, 168168000, 1, 60, 28440, 42045600, 76385194200, 155840192585280, 1, 180, 415800, 3216282300, 31168037156256, 342718542439257600, 3574641463338838464000, 1, 630, 8408400, 320818773240, 14181456923282880, 794364769671213312000, 40694019408428534970822000, 2416738787895064029335795945088]

cp's OEIS Frontend

A287021 Triangle read by rows: T(n,m) is the number of inequivalent n X m matrices under action of the Klein group, with one-fifth of 1s, 2s, 3s, 4s and 5s (ordered occurrences rounded up/down if n*m != 0 mod 5).

Table of values

List of values