A008550 formatted as a triangular array:
| | | | | | | | | | 1 | | | | | | | | | | |
| | | | | | | | | 1 | | 1 | | | | | | | | | |
| | | | | | | | 1 | | 1 | | 1 | | | | | | | | |
| | | | | | | 1 | | 2 | | 1 | | 1 | | | | | | | |
| | | | | | 1 | | 5 | | 3 | | 1 | | 1 | | | | | | |
| | | | | 1 | | 14 | | 11 | | 4 | | 1 | | 1 | | | | | |
| | | | 1 | | 42 | | 45 | | 19 | | 5 | | 1 | | 1 | | | | |
| | | 1 | | 132 | | 197 | | 100 | | 29 | | 6 | | 1 | | 1 | | | |
| | 1 | | 429 | | 903 | | 562 | | 185 | | 41 | | 7 | | 1 | | 1 | | |
| 1 | | 1430 | | 4279 | | 3304 | | 1257 | | 306 | | 55 | | 8 | | 1 | | 1 | |
| 1 | | 4862 | | 20793 | | 20071 | | 8925 | | 2426 | | 469 | | 71 | | 9 | | 1 | | 1 |
A008550 formatted as a square array:
| 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| 1 | 1 | 2 | 5 | 14 | 42 | 132 | 429 | 1430 | 4862 | |
| 1 | 1 | 3 | 11 | 45 | 197 | 903 | 4279 | 20793 | | |
| 1 | 1 | 4 | 19 | 100 | 562 | 3304 | 20071 | | | |
| 1 | 1 | 5 | 29 | 185 | 1257 | 8925 | | | | |
| 1 | 1 | 6 | 41 | 306 | 2426 | | | | | |
| 1 | 1 | 7 | 55 | 469 | | | | | | |
| 1 | 1 | 8 | 71 | | | | | | | |
| 1 | 1 | 9 | | | | | | | | |
| 1 | 1 | | | | | | | | | |
| 1 | | | | | | | | | | |
A008550 formatted as an upper right triangle:
| 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| 1 | 1 | 2 | 5 | 14 | 42 | 132 | 429 | 1430 | 4862 |
| | 1 | 1 | 3 | 11 | 45 | 197 | 903 | 4279 | 20793 |
| | | 1 | 1 | 4 | 19 | 100 | 562 | 3304 | 20071 |
| | | | 1 | 1 | 5 | 29 | 185 | 1257 | 8925 |
| | | | | 1 | 1 | 6 | 41 | 306 | 2426 |
| | | | | | 1 | 1 | 7 | 55 | 469 |
| | | | | | | 1 | 1 | 8 | 71 |
| | | | | | | | 1 | 1 | 9 |
| | | | | | | | | 1 | 1 |
| | | | | | | | | | 1 |
|
