The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 7 |
| 3 | 89 |
| 4 | 1831 |
| 5 | 5591 |
| 6 | 9551 |
| 7 | 89689 |
| 8 | 396733 |
| 9 | 3851459 |
| 10 | 11981443 |
| 11 | 70396393 |
| 12 | 202551667 |
| 13 | 1872851947 |
| 14 | 10958687879 |
| 15 | 47203303159 |
| 16 | 767644374817 |
| 17 | 1999066711391 |
| 18 | 8817792098461 |
| 19 | 78610833115261 |
| 20 | 497687231721157 |
| 21 | 2069461000669981 |
[2,7,89,1831,5591,9551,89689,396733,3851459, 11981443,70396393,202551667,1872851947, 10958687879,47203303159,767644374817, 1999066711391,8817792098461,78610833115261, 497687231721157,2069461000669981] |