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 | 7 |
| 3 | 26 |
| 4 | 90 |
| 5 | 340 |
| 6 | 1238 |
| 7 | 4647 |
| 8 | 17578 |
| 9 | 67592 |
| 10 | 259768 |
| 11 | 1004348 |
| 12 | 3902357 |
| 13 | 15202050 |
| 14 | 59410557 |
| 15 | 232483840 |
| 16 | 911689012 |
| 17 | 3581049040 |
| 18 | 14081089288 |
| 19 | 55439171531 |
| 20 | 218457593223 |
| 21 | 861617935051 |
| 22 | 3400917861268 |
| 23 | 13433148229639 |
| 24 | 53092686926155 |
| 25 | 209962593513292 |