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 | 2 |
| 1 | 13 |
| 2 | 151 |
| 3 | 1321 |
| 4 | 10627 |
| 5 | 79349 |
| 6 | 567871 |
| 7 | 3950183 |
| 8 | 26941241 |
| 9 | 180902089 |
| 10 | 1200241909 |
| 11 | 7886347793 |
| 12 | 51408151891 |
| 13 | 332894613817 |
| 14 | 2143561517329 |
| 15 | 13736049589111 |
| 16 | 87651481221089 |
| 17 | 557252522673659 |
| 18 | 3531220462434253 |
| 19 | 22311656552744543 |
| 20 | 140605761109553401 |
| 21 | 883994567552212601 |
| 22 | 5545829371444858669 |