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 | 13 |
| 2 | 57 |
| 3 | 377 |
| 4 | 1975 |
| 5 | 11385 |
| 6 | 61755 |
| 7 | 343035 |
| 8 | 1872913 |
| 9 | 10288475 |
| 10 | 56225061 |
| 11 | 307755285 |
| 12 | 1681755047 |
| 13 | 9194060283 |
| 14 | 50235380141 |
| 15 | 274514218163 |
| 16 | 1499800424044 |
| 17 | 8194423899045 |
| 18 | 44768307376625 |
| 19 | 244584423489933 |
| 20 | 1336207363455509 |