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 | 0 |
| 1 | 1 |
| 2 | 1025 |
| 3 | 60074 |
| 4 | 1108650 |
| 5 | 10874275 |
| 6 | 71340451 |
| 7 | 353815700 |
| 8 | 1427557524 |
| 9 | 4914341925 |
| 10 | 14914341925 |
| 11 | 40851766526 |
| 12 | 102769130750 |
| 13 | 240627622599 |
| 14 | 529882277575 |
| 15 | 1106532668200 |
| 16 | 2206044295976 |
| 17 | 4222038196425 |
| 18 | 7792505423049 |
| 19 | 13923571680850 |