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 | 0 |
| 1 | 1 |
| 2 | 6 |
| 3 | 42 |
| 4 | 346 |
| 5 | 3310 |
| 6 | 36194 |
| 7 | 446054 |
| 8 | 6122442 |
| 9 | 92668302 |
| 10 | 1533812722 |
| 11 | 27565147126 |
| 12 | 534621745178 |
| 13 | 11131104732254 |
| 14 | 247646911102530 |
| 15 | 5863652049020358 |
| 16 | 147225092025474154 |
| 17 | 3907328980930705966 |
| 18 | 109297865960259305618 |
| 19 | 3214017757399205062550 |
| 20 | 99121172016580291190970 |