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 | 2 |
| 2 | 11 |
| 3 | 61 |
| 4 | 359 |
| 5 | 2153 |
| 6 | 12917 |
| 7 | 77491 |
| 8 | 464941 |
| 9 | 2789629 |
| 10 | 16737761 |
| 11 | 100426553 |
| 12 | 602559311 |
| 13 | 3615355859 |
| 14 | 21692135119 |
| 15 | 130152810703 |
| 16 | 780916864207 |
| 17 | 4685501185193 |
| 18 | 28113007111153 |
| 19 | 168678042666907 |
| 20 | 1012068256001351 |
| 21 | 6072409536008087 |
| 22 | 36434457216048503 |
| 23 | 218606743296291011 |