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 | 3 |
| 2 | 11 |
| 3 | 41 |
| 4 | 147 |
| 5 | 509 |
| 6 | 1717 |
| 7 | 5671 |
| 8 | 18395 |
| 9 | 58735 |
| 10 | 184961 |
| 11 | 575337 |
| 12 | 1769981 |
| 13 | 5390997 |
| 14 | 16270587 |
| 15 | 48696299 |
| 16 | 144620059 |
| 17 | 426428645 |
| 18 | 1249007767 |
| 19 | 3635595953 |
| 20 | 10520770265 |
| 21 | 30278391475 |
| 22 | 86689798089 |
| 23 | 246988386691 |
| 24 | 700439171501 |
| 25 | 1977660342139 |
| 26 | 5560497703461 |