A180180 as a triangular array
| | | | | | | | | | | | 1 |
| | | | | | | | | | | | 1 | | 1 |
| | | | | | | | | | | 1 | | 2 | | 1 |
| | | | | | | | | | 1 | | 3 | | 3 | | 1 |
| | | | | | | | | 0 | | 4 | | 6 | | 4 | | 1 |
| | | | | | | | 1 | | 3 | | 10 | | 10 | | 5 | | 1 |
| | | | | | | 1 | | 4 | | 12 | | 20 | | 15 | | 6 | | 1 |
| | | | | | 1 | | 5 | | 15 | | 31 | | 35 | | 21 | | 7 | | 1 |
| | | | | 1 | | 6 | | 19 | | 44 | | 65 | | 56 | | 28 | | 8 | | 1 |
| | | | 1 | | 8 | | 24 | | 60 | | 106 | | 120 | | 84 | | 36 | | 9 | | 1 |
| | | 1 | | 8 | | 33 | | 80 | | 160 | | 222 | | 203 | | 120 | | 45 | | 10 | | 1 |
| | 1 | | 9 | | 40 | | 111 | | 230 | | 372 | | 420 | | 322 | | 165 | | 55 | | 11 | | 1 |
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A180180 as a square array
| 1 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1
| | 1 | 2 | 3 | 4 | 3 | 4 | 5 | 6 | 8 | 8 | 9
| | 1 | 3 | 6 | 10 | 12 | 15 | 19 | 24 | 33 | 40
| | 1 | 4 | 10 | 20 | 31 | 44 | 60 | 80 | 111
| | 1 | 5 | 15 | 35 | 65 | 106 | 160 | 230
| | 1 | 6 | 21 | 56 | 120 | 222 | 372
| | 1 | 7 | 28 | 84 | 203 | 420
| | 1 | 8 | 36 | 120 | 322
| | 1 | 9 | 45 | 165
| | 1 | 10 | 55
| | 1 | 11
| | 1
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A180180 as an upper right triangle
| 1 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1
| | 1 | 2 | 3 | 4 | 3 | 4 | 5 | 6 | 8 | 8 | 9
| | | 1 | 3 | 6 | 10 | 12 | 15 | 19 | 24 | 33 | 40
| | | | 1 | 4 | 10 | 20 | 31 | 44 | 60 | 80 | 111
| | | | | 1 | 5 | 15 | 35 | 65 | 106 | 160 | 230
| | | | | | 1 | 6 | 21 | 56 | 120 | 222 | 372
| | | | | | | 1 | 7 | 28 | 84 | 203 | 420
| | | | | | | | 1 | 8 | 36 | 120 | 322
| | | | | | | | | 1 | 9 | 45 | 165
| | | | | | | | | | 1 | 10 | 55
| | | | | | | | | | | 1 | 11
| | | | | | | | | | | | 1
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