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 | 2 |
| 3 | 3 |
| 4 | 4 |
| 5 | 5 |
| 6 | 26 |
| 7 | 2061 |
| 8 | 702993 |
| 9 | 307058572 |
| 10 | 3350187739 |
| 11 | 9088200428 |
| 12 | 43794115173 |
| 13 | 51932790219 |
| 14 | 378210209388 |
| 15 | 521301342188 |
| 16 | 297064987225918 |
| 17 | 19677201507658441 |
| 18 | 437852535314831447 |
| 19 | 1673669998972800207 |
| 20 | 29252504332047744188 |
| 21 | 42842701894337201916 |