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 | 0 |
| 1 | 1 |
| 2 | 3 |
| 3 | 14 |
| 4 | 57 |
| 5 | 229 |
| 6 | 916 |
| 7 | 7761 |
| 8 | 29567 |
| 9 | 117474 |
| 10 | 469113 |
| 11 | 3973641 |
| 12 | 15138352 |
| 13 | 60146777 |
| 14 | 240187355 |
| 15 | 2070207870 |
| 16 | 7733090689 |
| 17 | 30791909229 |
| 18 | 260408711716 |
| 19 | 991495872825 |
| 20 | 3942106110215 |
| 21 | 15739612088946 |
| 22 | 133333733918417 |