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 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 2 |
| 5 | 4 |
| 6 | 14 |
| 7 | 57 |
| 8 | 347 |
| 9 | 2375 |
| 10 | 20752 |
| 11 | 200805 |
| 12 | 2293192 |
| 13 | 28097136 |
| 14 | 381963696 |
| 15 | 5651257984 |
| 16 | 87997162749 |
| 17 | 1478237810536 |
| 18 | 26259254617337 |
| 19 | 491527066667949 |
| 20 | 9640606422165480 |