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Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 10 |
| 3 | 40 |
| 4 | 160 |
| 5 | 670 |
| 6 | 3001 |
| 7 | 13503 |
| 8 | 60408 |
| 9 | 270370 |
| 10 | 1192385 |
| 11 | 5221700 |
| 12 | 23404787 |
| 13 | 108379668 |
| 14 | 507618711 |
| 15 | 2353392292 |
| 16 | 10735523052 |
| 17 | 48337299889 |
| 18 | 216062343583 |
| 19 | 966793284879 |
| 20 | 4375808357962 |
| 21 | 20209591137998 |
| 22 | 95483805098650 |
[3,10,40,160,670,3001,13503,60408,270370,1192385, 5221700,23404787,108379668,507618711,2353392292, 10735523052,48337299889,216062343583,966793284879, 4375808357962,20209591137998,95483805098650] |