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 | 2 |
| 2 | 14 |
| 3 | 88 |
| 4 | 566 |
| 5 | 3722 |
| 6 | 24856 |
| 7 | 167868 |
| 8 | 1143462 |
| 9 | 7841434 |
| 10 | 54065574 |
| 11 | 374437404 |
| 12 | 2602879712 |
| 13 | 18150990238 |
| 14 | 126918338116 |
| 15 | 889551010728 |
| 16 | 6247598686710 |
| 17 | 43958881741086 |
| 18 | 309801915943318 |
| 19 | 2186512103767096 |
| 20 | 15452093394793006 |