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 | 1 |
| 2 | 5 |
| 3 | 32 |
| 4 | 278 |
| 5 | 3014 |
| 6 | 39226 |
| 7 | 595608 |
| 8 | 10335888 |
| 9 | 201785688 |
| 10 | 4377151464 |
| 11 | 104444584848 |
| 12 | 2718748442208 |
| 13 | 76668029954736 |
| 14 | 2328328726108368 |
| 15 | 75759574181169792 |
| 16 | 2629417097250852480 |
| 17 | 96963968323279825920 |
| 18 | 3786037089608099128320 |
| 19 | 156041617540423798782720 |