A131911 as a triangular array
| | | | | | | | | | 1 |
| | | | | | | | | | 4 | | 3 |
| | | | | | | | | 5 | | 2 | | 5 |
| | | | | | | | 8 | | 1 | | 2 | | 7 |
| | | | | | | 9 | | 2 | | 1 | | 2 | | 9 |
| | | | | | 12 | | 1 | | 2 | | 1 | | 2 | | 11 |
| | | | | 13 | | 2 | | 1 | | 2 | | 1 | | 2 | | 13 |
| | | | 16 | | 1 | | 2 | | 1 | | 2 | | 1 | | 2 | | 15 |
| | | 17 | | 2 | | 1 | | 2 | | 1 | | 2 | | 1 | | 2 | | 17 |
| | 20 | | 1 | | 2 | | 1 | | 2 | | 1 | | 2 | | 1 | | 2 | | 19 |
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A131911 as a square array
1 | 4 | 5 | 8 | 9 | 12 | 13 | 16 | 17 | 20
| 3 | 2 | 1 | 2 | 1 | 2 | 1 | 2 | 1
| 5 | 2 | 1 | 2 | 1 | 2 | 1 | 2
| 7 | 2 | 1 | 2 | 1 | 2 | 1
| 9 | 2 | 1 | 2 | 1 | 2
| 11 | 2 | 1 | 2 | 1
| 13 | 2 | 1 | 2
| 15 | 2 | 1
| 17 | 2
| 19
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A131911 as an upper right triangle
1 | 4 | 5 | 8 | 9 | 12 | 13 | 16 | 17 | 20
| | 3 | 2 | 1 | 2 | 1 | 2 | 1 | 2 | 1
| | | 5 | 2 | 1 | 2 | 1 | 2 | 1 | 2
| | | | 7 | 2 | 1 | 2 | 1 | 2 | 1
| | | | | 9 | 2 | 1 | 2 | 1 | 2
| | | | | | 11 | 2 | 1 | 2 | 1
| | | | | | | 13 | 2 | 1 | 2
| | | | | | | | 15 | 2 | 1
| | | | | | | | | 17 | 2
| | | | | | | | | | 19
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