A126890 formatted as a triangular array:
| | | | | | | | | | 0 | | | | | | | | | | |
| | | | | | | | | 1 | | 2 | | | | | | | | | |
| | | | | | | | 3 | | 5 | | 7 | | | | | | | | |
| | | | | | | 6 | | 9 | | 12 | | 15 | | | | | | | |
| | | | | | 10 | | 14 | | 18 | | 22 | | 26 | | | | | | |
| | | | | 15 | | 20 | | 25 | | 30 | | 35 | | 40 | | | | | |
| | | | 21 | | 27 | | 33 | | 39 | | 45 | | 51 | | 57 | | | | |
| | | 28 | | 35 | | 42 | | 49 | | 56 | | 63 | | 70 | | 77 | | | |
| | 36 | | 44 | | 52 | | 60 | | 68 | | 76 | | 84 | | 92 | | 100 | | |
| 45 | | 54 | | 63 | | 72 | | 81 | | 90 | | 99 | | 108 | | 117 | | 126 | |
| 55 | | 65 | | 75 | | 85 | | 95 | | 105 | | 115 | | 125 | | 135 | | 145 | | 155 |
A126890 formatted as a square array:
| 0 | 1 | 3 | 6 | 10 | 15 | 21 | 28 | 36 | 45 | 55 |
| 2 | 5 | 9 | 14 | 20 | 27 | 35 | 44 | 54 | 65 | |
| 7 | 12 | 18 | 25 | 33 | 42 | 52 | 63 | 75 | | |
| 15 | 22 | 30 | 39 | 49 | 60 | 72 | 85 | | | |
| 26 | 35 | 45 | 56 | 68 | 81 | 95 | | | | |
| 40 | 51 | 63 | 76 | 90 | 105 | | | | | |
| 57 | 70 | 84 | 99 | 115 | | | | | | |
| 77 | 92 | 108 | 125 | | | | | | | |
| 100 | 117 | 135 | | | | | | | | |
| 126 | 145 | | | | | | | | | |
| 155 | | | | | | | | | | |
A126890 formatted as an upper right triangle:
| 0 | 1 | 3 | 6 | 10 | 15 | 21 | 28 | 36 | 45 | 55 |
| 2 | 5 | 9 | 14 | 20 | 27 | 35 | 44 | 54 | 65 |
| | 7 | 12 | 18 | 25 | 33 | 42 | 52 | 63 | 75 |
| | | 15 | 22 | 30 | 39 | 49 | 60 | 72 | 85 |
| | | | 26 | 35 | 45 | 56 | 68 | 81 | 95 |
| | | | | 40 | 51 | 63 | 76 | 90 | 105 |
| | | | | | 57 | 70 | 84 | 99 | 115 |
| | | | | | | 77 | 92 | 108 | 125 |
| | | | | | | | 100 | 117 | 135 |
| | | | | | | | | 126 | 145 |
| | | | | | | | | | 155 |
|