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 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 14 |
| 4 | 42 |
| 5 | 132 |
| 6 | 430 |
| 7 | 1444 |
| 8 | 4981 |
| 9 | 17594 |
| 10 | 63441 |
| 11 | 232806 |
| 12 | 866870 |
| 13 | 3266460 |
| 14 | 12426210 |
| 15 | 47629020 |
| 16 | 183638729 |
| 17 | 711285170 |
| 18 | 2764753405 |
| 19 | 10775740030 |
| 20 | 42086252770 |
| 21 | 164635420788 |
| 22 | 644811687734 |
| 23 | 2527808259668 |
| 24 | 9916569410301 |
| 25 | 38923511495402 |
| 26 | 152841133694345 |
| 27 | 600349070362454 |