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 | 6 |
| 2 | 30 |
| 3 | 126 |
| 4 | 606 |
| 5 | 2766 |
| 6 | 13134 |
| 7 | 60990 |
| 8 | 286014 |
| 9 | 1333926 |
| 10 | 6235950 |
| 11 | 29160390 |
| 12 | 136280046 |
| 13 | 637801014 |
| 14 | 2981709558 |
| 15 | 13958158806 |
| 16 | 65278026174 |
| 17 | 305608333062 |
| 18 | 1429710254742 |
| 19 | 6693530115990 |
| 20 | 31322452467006 |
| 21 | 146644481901582 |
| 22 | 686366924272686 |
| 23 | 3213444320539710 |
| 24 | 15042778398965358 |