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 | 5 |
| 2 | 37 |
| 3 | 305 |
| 4 | 2641 |
| 5 | 23525 |
| 6 | 213445 |
| 7 | 1961825 |
| 8 | 18205345 |
| 9 | 170195525 |
| 10 | 1600472677 |
| 11 | 15122515985 |
| 12 | 143457011569 |
| 13 | 1365435096485 |
| 14 | 13033485491077 |
| 15 | 124715953657025 |
| 16 | 1195966908404545 |
| 17 | 11490534389896325 |
| 18 | 110584004488276645 |
| 19 | 1065853221648055025 |