A033820 formatted as a triangular array:
| | | | | | | | 1 | | | | | | | | |
| | | | | | | 1 | | 3 | | | | | | | |
| | | | | | 2 | | 4 | | 10 | | | | | | |
| | | | | 5 | | 9 | | 15 | | 35 | | | | | |
| | | | 14 | | 24 | | 36 | | 56 | | 126 | | | | |
| | | 42 | | 70 | | 100 | | 140 | | 210 | | 462 | | | |
| | 132 | | 216 | | 300 | | 400 | | 540 | | 792 | | 1716 | | |
| 429 | | 693 | | 945 | | 1225 | | 1575 | | 2079 | | 3003 | | 6435 | |
| 1430 | | 2288 | | 3080 | | 3920 | | 4900 | | 6160 | | 8008 | | 11440 | | 24310 |
A033820 formatted as a square array:
| 1 | 1 | 2 | 5 | 14 | 42 | 132 | 429 | 1430 |
| 3 | 4 | 9 | 24 | 70 | 216 | 693 | 2288 | |
| 10 | 15 | 36 | 100 | 300 | 945 | 3080 | | |
| 35 | 56 | 140 | 400 | 1225 | 3920 | | | |
| 126 | 210 | 540 | 1575 | 4900 | | | | |
| 462 | 792 | 2079 | 6160 | | | | | |
| 1716 | 3003 | 8008 | | | | | | |
| 6435 | 11440 | | | | | | | |
| 24310 | | | | | | | | |
A033820 formatted as an upper right triangle:
| 1 | 1 | 2 | 5 | 14 | 42 | 132 | 429 | 1430 |
| 3 | 4 | 9 | 24 | 70 | 216 | 693 | 2288 |
| | 10 | 15 | 36 | 100 | 300 | 945 | 3080 |
| | | 35 | 56 | 140 | 400 | 1225 | 3920 |
| | | | 126 | 210 | 540 | 1575 | 4900 |
| | | | | 462 | 792 | 2079 | 6160 |
| | | | | | 1716 | 3003 | 8008 |
| | | | | | | 6435 | 11440 |
| | | | | | | | 24310 |
|