A026780 as a triangular array
| | | | | | | | | | | 1 |
| | | | | | | | | | | 1 | | 1 |
| | | | | | | | | | 1 | | 3 | | 1 |
| | | | | | | | | 1 | | 5 | | 4 | | 1 |
| | | | | | | | 1 | | 7 | | 12 | | 5 | | 1 |
| | | | | | | 1 | | 9 | | 24 | | 17 | | 6 | | 1 |
| | | | | | 1 | | 11 | | 40 | | 53 | | 23 | | 7 | | 1 |
| | | | | 1 | | 13 | | 60 | | 117 | | 76 | | 30 | | 8 | | 1 |
| | | | 1 | | 15 | | 84 | | 217 | | 246 | | 106 | | 38 | | 9 | | 1 |
| | | 1 | | 17 | | 112 | | 361 | | 580 | | 352 | | 144 | | 47 | | 10 | | 1 |
| | 1 | | 19 | | 144 | | 557 | | 1158 | | 1178 | | 496 | | 191 | | 57 | | 11 | | 1 |
|
A026780 as a square array
| 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1
| | 1 | 3 | 5 | 7 | 9 | 11 | 13 | 15 | 17 | 19
| | 1 | 4 | 12 | 24 | 40 | 60 | 84 | 112 | 144
| | 1 | 5 | 17 | 53 | 117 | 217 | 361 | 557
| | 1 | 6 | 23 | 76 | 246 | 580 | 1158
| | 1 | 7 | 30 | 106 | 352 | 1178
| | 1 | 8 | 38 | 144 | 496
| | 1 | 9 | 47 | 191
| | 1 | 10 | 57
| | 1 | 11
| | 1
|
A026780 as an upper right triangle
| 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1
| | 1 | 3 | 5 | 7 | 9 | 11 | 13 | 15 | 17 | 19
| | | 1 | 4 | 12 | 24 | 40 | 60 | 84 | 112 | 144
| | | | 1 | 5 | 17 | 53 | 117 | 217 | 361 | 557
| | | | | 1 | 6 | 23 | 76 | 246 | 580 | 1158
| | | | | | 1 | 7 | 30 | 106 | 352 | 1178
| | | | | | | 1 | 8 | 38 | 144 | 496
| | | | | | | | 1 | 9 | 47 | 191
| | | | | | | | | 1 | 10 | 57
| | | | | | | | | | 1 | 11
| | | | | | | | | | | 1
|
|
