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 | 4 |
| 3 | 27 |
| 4 | 257 |
| 5 | 3157 |
| 6 | 47385 |
| 7 | 839928 |
| 8 | 17168097 |
| 9 | 397517868 |
| 10 | 10283523826 |
| 11 | 293950435376 |
| 12 | 9200707298514 |
| 13 | 312972062711525 |
| 14 | 11496160809184370 |
| 15 | 453507273286873875 |
| 16 | 19122193920118268355 |
| 17 | 858239308206920523297 |
| 18 | 40851073484808464297979 |