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 | 9 |
| 4 | 37 |
| 5 | 169 |
| 6 | 981 |
| 7 | 6429 |
| 8 | 49669 |
| 9 | 430861 |
| 10 | 4208925 |
| 11 | 45345165 |
| 12 | 536229373 |
| 13 | 6884917597 |
| 14 | 95473049469 |
| 15 | 1420609412637 |
| 16 | 22580588347741 |
| 17 | 381713065286173 |
| 18 | 6837950790434781 |
| 19 | 129378941557961565 |
| 20 | 2578133190722896861 |
| 21 | 53965646957320869469 |
| 22 | 1183822028149936497501 |