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 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 7 |
| 5 | 16 |
| 6 | 128 |
| 7 | 955 |
| 8 | 13467 |
| 9 | 253373 |
| 10 | 6466074 |
| 11 | 205749149 |
| 12 | 7943313377 |
| 13 | 363853255012 |
| 14 | 19485170158346 |
| 15 | 1205488841884007 |
| 16 | 85308028236495340 |
| 17 | 6846462326434510551 |
| 18 | 618498122199399056707 |
| 19 | 62478078728492272712838 |
| 20 | 7015617595855429187696753 |