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 | 1 |
| 3 | 3 |
| 4 | 19 |
| 5 | 195 |
| 6 | 3031 |
| 7 | 67263 |
| 8 | 2086099 |
| 9 | 89224635 |
| 10 | 5254054111 |
| 11 | 426609529863 |
| 12 | 47982981969979 |
| 13 | 7507894696005795 |
| 14 | 1641072554263066471 |
| 15 | 502596525992239961103 |
| 16 | 216218525837808950623459 |
| 17 | 130887167385831881114006475 |
| 18 | 111653218763166828863141636911 |