A010027 formatted as a triangular array:
| | | | | | | | | 1 | | | | | | | | | |
| | | | | | | | 1 | | 1 | | | | | | | | |
| | | | | | | 1 | | 2 | | 3 | | | | | | | |
| | | | | | 1 | | 3 | | 9 | | 11 | | | | | | |
| | | | | 1 | | 4 | | 18 | | 44 | | 53 | | | | | |
| | | | 1 | | 5 | | 30 | | 110 | | 265 | | 309 | | | | |
| | | 1 | | 6 | | 45 | | 220 | | 795 | | 1854 | | 2119 | | | |
| | 1 | | 7 | | 63 | | 385 | | 1855 | | 6489 | | 14833 | | 16687 | | |
| 1 | | 8 | | 84 | | 616 | | 3710 | | 17304 | | 59332 | | 133496 | | 148329 | |
| 1 | | 9 | | 108 | | 924 | | 6678 | | 38934 | | 177996 | | 600732 | | 1334961 | | 1468457 |
A010027 formatted as a square array:
| 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | |
| 3 | 9 | 18 | 30 | 45 | 63 | 84 | 108 | | |
| 11 | 44 | 110 | 220 | 385 | 616 | 924 | | | |
| 53 | 265 | 795 | 1855 | 3710 | 6678 | | | | |
| 309 | 1854 | 6489 | 17304 | 38934 | | | | | |
| 2119 | 14833 | 59332 | 177996 | | | | | | |
| 16687 | 133496 | 600732 | | | | | | | |
| 148329 | 1334961 | | | | | | | | |
| 1468457 | | | | | | | | | |
A010027 formatted as an upper right triangle:
| 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
| | 3 | 9 | 18 | 30 | 45 | 63 | 84 | 108 |
| | | 11 | 44 | 110 | 220 | 385 | 616 | 924 |
| | | | 53 | 265 | 795 | 1855 | 3710 | 6678 |
| | | | | 309 | 1854 | 6489 | 17304 | 38934 |
| | | | | | 2119 | 14833 | 59332 | 177996 |
| | | | | | | 16687 | 133496 | 600732 |
| | | | | | | | 148329 | 1334961 |
| | | | | | | | | 1468457 |
|
