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Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 5 |
| 5 | 15 |
| 6 | 50 |
| 7 | 180 |
| 8 | 676 |
| 9 | 2666 |
| 10 | 10831 |
| 11 | 45263 |
| 12 | 193097 |
| 13 | 839305 |
| 14 | 3702793 |
| 15 | 16552491 |
| 16 | 74829186 |
| 17 | 341652547 |
| 18 | 1573557441 |
| 19 | 7303953109 |
| 20 | 34139363401 |
| 21 | 160575404720 |
| 22 | 759577584604 |
| 23 | 3611720900930 |
| 24 | 17254901764792 |
| 25 | 82793934434748 |
| 26 | 398862862215977 |
| 27 | 1928661772504001 |
| 28 | 9357906461877107 |
| 29 | 45549820100444687 |
[0,1,1,1,5,15,50,180,676,2666,10831,45263,193097, 839305,3702793,16552491,74829186,341652547, 1573557441,7303953109,34139363401,160575404720, 759577584604,3611720900930,17254901764792, 82793934434748,398862862215977,1928661772504001, 9357906461877107,45549820100444687] |