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 | 17 |
| 4 | 101 |
| 5 | 589 |
| 6 | 4369 |
| 7 | 35125 |
| 8 | 323273 |
| 9 | 3263129 |
| 10 | 36301661 |
| 11 | 439023001 |
| 12 | 5748342445 |
| 13 | 80949641317 |
| 14 | 1220505157481 |
| 15 | 19615065647549 |
| 16 | 334764933094289 |
| 17 | 6046684538094385 |
| 18 | 115242737561241013 |
| 19 | 2311256839666971169 |
| 20 | 48658040610273601781 |
| 21 | 1072909782649220737661 |