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 | 5 |
| 2 | 19 |
| 3 | 80 |
| 4 | 343 |
| 5 | 1475 |
| 6 | 6346 |
| 7 | 27305 |
| 8 | 117487 |
| 9 | 505520 |
| 10 | 2175139 |
| 11 | 9359135 |
| 12 | 40270258 |
| 13 | 173273885 |
| 14 | 745558651 |
| 15 | 3207971600 |
| 16 | 13803182047 |
| 17 | 59391995435 |
| 18 | 255550431034 |
| 19 | 1099576168865 |
| 20 | 4731229551223 |
| 21 | 20357419249520 |
| 22 | 87593407593931 |
| 23 | 376894780221095 |
| 24 | 1621693678323682 |