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 | 6 |
| 2 | 96 |
| 3 | 654 |
| 4 | 4938 |
| 5 | 33502 |
| 6 | 221672 |
| 7 | 1426734 |
| 8 | 9014839 |
| 9 | 56128696 |
| 10 | 345447208 |
| 11 | 2106033948 |
| 12 | 12739126739 |
| 13 | 76548375758 |
| 14 | 457375097789 |
| 15 | 2719454021744 |
| 16 | 16100269337597 |
| 17 | 94961606031670 |
| 18 | 558226473615469 |
| 19 | 3271710478901046 |
| 20 | 19123726111508773 |
| 21 | 111510459865449832 |