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 | 3 |
| 5 | 11 |
| 6 | 38 |
| 7 | 130 |
| 8 | 638 |
| 9 | 4158 |
| 10 | 23384 |
| 11 | 124520 |
| 12 | 847484 |
| 13 | 6987380 |
| 14 | 53746000 |
| 15 | 400346544 |
| 16 | 3529108816 |
| 17 | 35963592624 |
| 18 | 351432650816 |
| 19 | 3346590201888 |
| 20 | 36341624453568 |