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Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 4 |
| 3 | 14 |
| 4 | 40 |
| 5 | 110 |
| 6 | 280 |
| 7 | 698 |
| 8 | 1696 |
| 9 | 4052 |
| 10 | 9564 |
| 11 | 22330 |
| 12 | 51728 |
| 13 | 118998 |
| 14 | 272228 |
| 15 | 619804 |
| 16 | 1405456 |
| 17 | 3175966 |
| 18 | 7155320 |
| 19 | 16078698 |
| 20 | 36048008 |
| 21 | 80656900 |
| 22 | 180149700 |
| 23 | 401740002 |
| 24 | 894646944 |
| 25 | 1989842814 |
| 26 | 4420825196 |
| 27 | 9811946668 |
| 28 | 21757950712 |
| 29 | 48209235558 |
[0,4,14,40,110,280,698,1696,4052,9564,22330,51728, 118998,272228,619804,1405456,3175966,7155320, 16078698,36048008,80656900,180149700,401740002, 894646944,1989842814,4420825196,9811946668, 21757950712,48209235558] |