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 | 0 |
| 2 | 1 |
| 3 | 8 |
| 4 | 49 |
| 5 | 284 |
| 6 | 1658 |
| 7 | 9974 |
| 8 | 62375 |
| 9 | 406832 |
| 10 | 2769493 |
| 11 | 19668054 |
| 12 | 145559632 |
| 13 | 1121153604 |
| 14 | 8974604065 |
| 15 | 74553168520 |
| 16 | 641808575961 |
| 17 | 5718014325296 |
| 18 | 52653303354906 |
| 19 | 500515404889978 |
| 20 | 4905937052293759 |
| 21 | 49530189989912312 |
| 22 | 514541524981377909 |
| 23 | 5494885265473192914 |