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 | 7 |
| 4 | 35 |
| 5 | 193 |
| 6 | 1799 |
| 7 | 19311 |
| 8 | 254143 |
| 9 | 3828921 |
| 10 | 65486307 |
| 11 | 1249937335 |
| 12 | 26353147811 |
| 13 | 608142583137 |
| 14 | 15247011443103 |
| 15 | 412685556939751 |
| 16 | 11993674252049647 |
| 17 | 372509404162520641 |
| 18 | 12313505313357313047 |
| 19 | 431620764875678503143 |
| 20 | 15991549339008732109899 |