A121281 as a triangular array
| | | | | | | | | 1 |
| | | | | | | | | 2 | | 1 |
| | | | | | | | 6 | | 3 | | 2 |
| | | | | | | 30 | | 15 | | 10 | | 6 |
| | | | | | 210 | | 105 | | 70 | | 42 | | 30 |
| | | | | 2310 | | 1155 | | 770 | | 462 | | 330 | | 210 |
| | | | 30030 | | 15015 | | 10010 | | 6006 | | 4290 | | 2730 | | 2310 |
| | | 510510 | | 255255 | | 170170 | | 102102 | | 72930 | | 46410 | | 39270 | | 30030 |
| | 9699690 | | 4849845 | | 3233230 | | 1939938 | | 1385670 | | 881790 | | 746130 | | 570570 | | 510510 |
|
A121281 as a square array
1 | 2 | 6 | 30 | 210 | 2310 | 30030 | 510510 | 9699690
| 1 | 3 | 15 | 105 | 1155 | 15015 | 255255 | 4849845
| 2 | 10 | 70 | 770 | 10010 | 170170 | 3233230
| 6 | 42 | 462 | 6006 | 102102 | 1939938
| 30 | 330 | 4290 | 72930 | 1385670
| 210 | 2730 | 46410 | 881790
| 2310 | 39270 | 746130
| 30030 | 570570
| 510510
|
A121281 as an upper right triangle
1 | 2 | 6 | 30 | 210 | 2310 | 30030 | 510510 | 9699690
| | 1 | 3 | 15 | 105 | 1155 | 15015 | 255255 | 4849845
| | | 2 | 10 | 70 | 770 | 10010 | 170170 | 3233230
| | | | 6 | 42 | 462 | 6006 | 102102 | 1939938
| | | | | 30 | 330 | 4290 | 72930 | 1385670
| | | | | | 210 | 2730 | 46410 | 881790
| | | | | | | 2310 | 39270 | 746130
| | | | | | | | 30030 | 570570
| | | | | | | | | 510510
|
|