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 | 4 |
| 4 | 15 |
| 5 | 68 |
| 6 | 322 |
| 7 | 1608 |
| 8 | 8283 |
| 9 | 43780 |
| 10 | 235950 |
| 11 | 1291992 |
| 12 | 7167030 |
| 13 | 40192488 |
| 14 | 227488900 |
| 15 | 1297845008 |
| 16 | 7455558675 |
| 17 | 43088726148 |
| 18 | 250362137590 |
| 19 | 1461641062200 |
| 20 | 8569690323810 |
| 21 | 50438119336440 |
| 22 | 297896152159260 |
| 23 | 1765010252344560 |
| 24 | 10487875429825950 |
| 25 | 62485899131628648 |
| 26 | 373198022044163532 |