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 | 52 |
| 2 | 834 |
| 3 | 4760 |
| 4 | 24703 |
| 5 | 94980 |
| 6 | 343998 |
| 7 | 1077496 |
| 8 | 3222915 |
| 9 | 8844712 |
| 10 | 23381058 |
| 11 | 58359168 |
| 12 | 141244796 |
| 13 | 327974700 |
| 14 | 742169724 |
| 15 | 1627202744 |
| 16 | 3490345477 |
| 17 | 7301071680 |
| 18 | 14987511560 |
| 19 | 30138820888 |
| 20 | 59623576440 |
| 21 | 115928963656 |