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 | 3 |
| 2 | 11 |
| 3 | 51 |
| 4 | 307 |
| 5 | 2451 |
| 6 | 26387 |
| 7 | 387987 |
| 8 | 7866259 |
| 9 | 221472147 |
| 10 | 8703733139 |
| 11 | 479243212179 |
| 12 | 37070813107603 |
| 13 | 4036214347068819 |
| 14 | 619402703369958803 |
| 15 | 134108807406166799763 |
| 16 | 40994263184865380595091 |
| 17 | 17700624176280878586721683 |
| 18 | 10799420012335823235718509971 |