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 | 9 |
| 3 | 31 |
| 4 | 140 |
| 5 | 571 |
| 6 | 2413 |
| 7 | 10069 |
| 8 | 42205 |
| 9 | 176624 |
| 10 | 739573 |
| 11 | 3096173 |
| 12 | 12962845 |
| 13 | 54270579 |
| 14 | 227212636 |
| 15 | 951259751 |
| 16 | 3982596009 |
| 17 | 16673747193 |
| 18 | 69807202249 |
| 19 | 292258553696 |
| 20 | 1223585260409 |
| 21 | 5122727328297 |
| 22 | 21447083573633 |
| 23 | 89791504401207 |