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 | 2 |
| 2 | 5 |
| 3 | 16 |
| 4 | 89 |
| 5 | 686 |
| 6 | 5917 |
| 7 | 54860 |
| 8 | 588401 |
| 9 | 7370074 |
| 10 | 103522421 |
| 11 | 1573237832 |
| 12 | 25869057865 |
| 13 | 462768222086 |
| 14 | 8965777751309 |
| 15 | 186025937645956 |
| 16 | 4106375449878497 |
| 17 | 96241703493486770 |
| 18 | 2390797380938894821 |
| 19 | 62730027061416412544 |