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 | 1 |
| 2 | 4 |
| 3 | 26 |
| 4 | 260 |
| 5 | 3610 |
| 6 | 64472 |
| 7 | 1409006 |
| 8 | 36432076 |
| 9 | 1087911890 |
| 10 | 36844580000 |
| 11 | 1395429571222 |
| 12 | 58439837713556 |
| 13 | 2681526361893626 |
| 14 | 133783187672365480 |
| 15 | 7210345924097089790 |
| 16 | 417482356526745344732 |
| 17 | 25844171201928905477026 |
| 18 | 1703359919973405018460976 |