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) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 17 |
| 4 | 111 |
| 5 | 762 |
| 6 | 4095 |
| 7 | 19941 |
| 8 | 84825 |
| 9 | 329214 |
| 10 | 1168740 |
| 11 | 3858348 |
| 12 | 11920740 |
| 13 | 34773590 |
| 14 | 96282900 |
| 15 | 254473884 |
| 16 | 644637204 |
| 17 | 1571330916 |
| 18 | 3697182450 |
| 19 | 8421423582 |
| 20 | 18615637950 |
| 21 | 40023753924 |
| 22 | 83859017814 |
| 23 | 171530071362 |
| 24 | 343059613650 |
| 25 | 671825586021 |
| 26 | 1289904147324 |
| 27 | 2430974136780 |