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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 4 |
| 3 | 6 |
| 4 | 10 |
| 5 | 15 |
| 6 | 22 |
| 7 | 28 |
| 8 | 36 |
| 9 | 45 |
| 10 | 56 |
| 11 | 66 |
| 12 | 78 |
| 13 | 91 |
| 14 | 106 |
| 15 | 120 |
| 16 | 136 |
| 17 | 153 |
| 18 | 172 |
| 19 | 190 |
| 20 | 210 |
| 21 | 231 |
| 22 | 254 |
| 23 | 276 |
| 24 | 300 |
| 25 | 325 |
| 26 | 352 |
| 27 | 378 |
| 28 | 406 |
| 29 | 435 |
| 30 | 466 |
| 31 | 496 |
| 32 | 528 |
| 33 | 561 |
| 34 | 596 |
| 35 | 630 |
| 36 | 666 |
| 37 | 703 |
| 38 | 742 |
| 39 | 780 |
| 40 | 820 |
| 41 | 861 |
| 42 | 904 |
| 43 | 946 |
| 44 | 990 |
| 45 | 1035 |
| 46 | 1082 |
| 47 | 1128 |
| 48 | 1176 |
| 49 | 1225 |
[0,1,4,6,10,15,22,28,36,45,56,66,78,91,106,120, 136,153,172,190,210,231,254,276,300,325,352,378, 406,435,466,496,528,561,596,630,666,703,742,780, 820,861,904,946,990,1035,1082,1128,1176,1225] |