| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 6 |
| 3 | 10 |
| 4 | 15 |
| 5 | 20 |
| 6 | 27 |
| 7 | 34 |
| 8 | 42 |
| 9 | 51 |
| 10 | 61 |
| 11 | 71 |
| 12 | 83 |
| 13 | 94 |
| 14 | 106 |
| 15 | 120 |
| 16 | 135 |
| 17 | 148 |
| 18 | 165 |
| 19 | 180 |
| 20 | 198 |
| 21 | 216 |
| 22 | 235 |
| 23 | 252 |
| 24 | 273 |
| 25 | 294 |
| 26 | 315 |
| 27 | 337 |
| 28 | 360 |
| 29 | 382 |
| 30 | 408 |
| 31 | 431 |
| 32 | 457 |
| 33 | 484 |
| 34 | 508 |
| 35 | 536 |
| 36 | 567 |
| 37 | 595 |
| 38 | 624 |
| 39 | 653 |
| 40 | 687 |
| 41 | 715 |
| 42 | 749 |
| 43 | 781 |
| 44 | 813 |
| 45 | 850 |
| 46 | 884 |
| 47 | 919 |
| 48 | 957 |
| 49 | 993 |
| 50 | 1031 |
| 51 | 1069 |
| 52 | 1108 |
| 53 | 1142 |
[1,3,6,10,15,20,27,34,42,51,61,71,83,94,106,120, 135,148,165,180,198,216,235,252,273,294,315,337, 360,382,408,431,457,484,508,536,567,595,624,653, 687,715,749,781,813,850,884,919,957,993,1031,1069, 1108,1142] |