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 | 4 |
| 3 | 9 |
| 4 | 22 |
| 5 | 57 |
| 6 | 154 |
| 7 | 429 |
| 8 | 1223 |
| 9 | 3550 |
| 10 | 10455 |
| 11 | 31160 |
| 12 | 93802 |
| 13 | 284789 |
| 14 | 871008 |
| 15 | 2681019 |
| 16 | 8298933 |
| 17 | 25817396 |
| 18 | 80674902 |
| 19 | 253106837 |
| 20 | 796968056 |
| 21 | 2517706037 |
| 22 | 7977573203 |
| 23 | 25347126630 |
| 24 | 80738862085 |
| 25 | 257778971504 |
| 26 | 824798533933 |