This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 11 |
| 4 | 46 |
| 5 | 209 |
| 6 | 1006 |
| 7 | 5053 |
| 8 | 26227 |
| 9 | 139726 |
| 10 | 760398 |
| 11 | 4211959 |
| 12 | 23681987 |
| 13 | 134869448 |
| 14 | 776657383 |
| 15 | 4516117107 |
| 16 | 26486641078 |
| 17 | 156532100029 |
| 18 | 931426814462 |
| 19 | 5576590927886 |
| 20 | 33574649282538 |
| 21 | 203169756237944 |
| 22 | 1235156720288767 |
| 23 | 7541099028832261 |
| 24 | 46222213821431646 |