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 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 9 |
| 5 | 21 |
| 6 | 51 |
| 7 | 127 |
| 8 | 322 |
| 9 | 826 |
| 10 | 2135 |
| 11 | 5545 |
| 12 | 14445 |
| 13 | 37701 |
| 14 | 98514 |
| 15 | 257608 |
| 16 | 673933 |
| 17 | 1763581 |
| 18 | 4615823 |
| 19 | 12082291 |
| 20 | 31628466 |
| 21 | 82798926 |
| 22 | 216761547 |
| 23 | 567474769 |
| 24 | 1485645049 |
| 25 | 3889431721 |
| 26 | 10182603746 |
| 27 | 26658304492 |
| 28 | 69792188337 |
| 29 | 182718064101 |
| 30 | 478361686155 |
| 31 | 1252366480135 |