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 | 5 |
| 3 | 31 |
| 4 | 229 |
| 5 | 1832 |
| 6 | 15583 |
| 7 | 137791 |
| 8 | 1255202 |
| 9 | 11693697 |
| 10 | 110905169 |
| 11 | 1067181020 |
| 12 | 10392861567 |
| 13 | 102239342761 |
| 14 | 1014484221699 |
| 15 | 10141596951782 |
| 16 | 102044286177390 |
| 17 | 1032652191535027 |
| 18 | 10503201188806574 |
| 19 | 107313868098732336 |
| 20 | 1100922685481490057 |
| 21 | 11335843298568212815 |
| 22 | 117111555943587032146 |
| 23 | 1213575764038590524010 |