A215561 as a triangular array
| | | | | | | | | | 1 |
| | | | | | | | | | 1 | | 1 |
| | | | | | | | | 1 | | 1 | | 1 |
| | | | | | | | 1 | | 1 | | 1 | | 1 |
| | | | | | | 1 | | 1 | | 2 | | 3 | | 1 |
| | | | | | 1 | | 1 | | 5 | | 30 | | 7 | | 1 |
| | | | | 1 | | 1 | | 14 | | 420 | | 403 | | 35 | | 1 |
| | | | 1 | | 1 | | 42 | | 6930 | | 40350 | | 18720 | | 139 | | 1 |
| | | 1 | | 1 | | 132 | | 126126 | | 5223915 | | 19369350 | | 746192 | | 1001 | | 1 |
| | 1 | | 1 | | 429 | | 2450448 | | 783353872 | | 27032968200 | | 9212531290 | | 71892912 | | 5701 | | 1 |
|
A215561 as a square array
1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1
| 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1
| 1 | 1 | 2 | 5 | 14 | 42 | 132 | 429
| 1 | 3 | 30 | 420 | 6930 | 126126 | 2450448
| 1 | 7 | 403 | 40350 | 5223915 | 783353872
| 1 | 35 | 18720 | 19369350 | 27032968200
| 1 | 139 | 746192 | 9212531290
| 1 | 1001 | 71892912
| 1 | 5701
| 1
|
A215561 as an upper right triangle
1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1
| | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1
| | | 1 | 1 | 2 | 5 | 14 | 42 | 132 | 429
| | | | 1 | 3 | 30 | 420 | 6930 | 126126 | 2450448
| | | | | 1 | 7 | 403 | 40350 | 5223915 | 783353872
| | | | | | 1 | 35 | 18720 | 19369350 | 27032968200
| | | | | | | 1 | 139 | 746192 | 9212531290
| | | | | | | | 1 | 1001 | 71892912
| | | | | | | | | 1 | 5701
| | | | | | | | | | 1
|
|