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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 6 |
| 2 | 21 |
| 3 | 56 |
| 4 | 131 |
| 5 | 286 |
| 6 | 601 |
| 7 | 1236 |
| 8 | 2511 |
| 9 | 5066 |
| 10 | 10181 |
| 11 | 20416 |
| 12 | 40891 |
| 13 | 81846 |
| 14 | 163761 |
| 15 | 327596 |
| 16 | 655271 |
| 17 | 1310626 |
| 18 | 2621341 |
| 19 | 5242776 |
| 20 | 10485651 |
| 21 | 20971406 |
| 22 | 41942921 |
| 23 | 83885956 |
| 24 | 167772031 |
| 25 | 335544186 |
| 26 | 671088501 |
| 27 | 1342177136 |
| 28 | 2684354411 |
| 29 | 5368708966 |
| 30 | 10737418081 |
[1,6,21,56,131,286,601,1236,2511,5066,10181,20416, 40891,81846,163761,327596,655271,1310626,2621341, 5242776,10485651,20971406,41942921,83885956, 167772031,335544186,671088501,1342177136, 2684354411,5368708966,10737418081] |