A028657 as a triangular array
| | | | | | | | | | | | 1 |
| | | | | | | | | | | | 1 | | 1 |
| | | | | | | | | | | 1 | | 2 | | 1 |
| | | | | | | | | | 1 | | 3 | | 3 | | 1 |
| | | | | | | | | 1 | | 4 | | 7 | | 4 | | 1 |
| | | | | | | | 1 | | 5 | | 13 | | 13 | | 5 | | 1 |
| | | | | | | 1 | | 6 | | 22 | | 36 | | 22 | | 6 | | 1 |
| | | | | | 1 | | 7 | | 34 | | 87 | | 87 | | 34 | | 7 | | 1 |
| | | | | 1 | | 8 | | 50 | | 190 | | 317 | | 190 | | 50 | | 8 | | 1 |
| | | | 1 | | 9 | | 70 | | 386 | | 1053 | | 1053 | | 386 | | 70 | | 9 | | 1 |
| | | 1 | | 10 | | 95 | | 734 | | 3250 | | 5624 | | 3250 | | 734 | | 95 | | 10 | | 1 |
| | 1 | | 11 | | 125 | | 1324 | | 9343 | | 28576 | | 28576 | | 9343 | | 1324 | | 125 | | 11 | | 1 |
|
A028657 as a square array
| 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1
| | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11
| | 1 | 3 | 7 | 13 | 22 | 34 | 50 | 70 | 95 | 125
| | 1 | 4 | 13 | 36 | 87 | 190 | 386 | 734 | 1324
| | 1 | 5 | 22 | 87 | 317 | 1053 | 3250 | 9343
| | 1 | 6 | 34 | 190 | 1053 | 5624 | 28576
| | 1 | 7 | 50 | 386 | 3250 | 28576
| | 1 | 8 | 70 | 734 | 9343
| | 1 | 9 | 95 | 1324
| | 1 | 10 | 125
| | 1 | 11
| | 1
|
A028657 as an upper right triangle
| 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1
| | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11
| | | 1 | 3 | 7 | 13 | 22 | 34 | 50 | 70 | 95 | 125
| | | | 1 | 4 | 13 | 36 | 87 | 190 | 386 | 734 | 1324
| | | | | 1 | 5 | 22 | 87 | 317 | 1053 | 3250 | 9343
| | | | | | 1 | 6 | 34 | 190 | 1053 | 5624 | 28576
| | | | | | | 1 | 7 | 50 | 386 | 3250 | 28576
| | | | | | | | 1 | 8 | 70 | 734 | 9343
| | | | | | | | | 1 | 9 | 95 | 1324
| | | | | | | | | | 1 | 10 | 125
| | | | | | | | | | | 1 | 11
| | | | | | | | | | | | 1
|
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