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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 2 |
| 4 | 6 |
| 5 | 26 |
| 6 | 31 |
| 7 | 66 |
| 8 | 126 |
| 9 | 156 |
| 10 | 626 |
| 11 | 651 |
| 12 | 756 |
| 13 | 804 |
| 14 | 3126 |
| 15 | 3276 |
| 16 | 3756 |
| 17 | 9054 |
| 18 | 15626 |
| 19 | 15751 |
| 20 | 16276 |
| 21 | 18434 |
| 22 | 18756 |
| 23 | 32578 |
| 24 | 34162 |
| 25 | 46704 |
| 26 | 78126 |
| 27 | 78876 |
| 28 | 81276 |
| 29 | 93756 |
| 30 | 390626 |
| 31 | 391251 |
| 32 | 393876 |
| 33 | 406276 |
| 34 | 468756 |
| 35 | 487981 |
| 36 | 1166454 |
| 37 | 1953126 |
| 38 | 1956876 |
[0,1,2,6,26,31,66,126,156,626,651,756,804,3126, 3276,3756,9054,15626,15751,16276,18434,18756, 32578,34162,46704,78126,78876,81276,93756,390626, 391251,393876,406276,468756,487981,1166454, 1953126,1956876] |