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 | 12 |
| 3 | 50 |
| 4 | 211 |
| 5 | 895 |
| 6 | 3805 |
| 7 | 16193 |
| 8 | 68940 |
| 9 | 293526 |
| 10 | 1249622 |
| 11 | 5318976 |
| 12 | 22634700 |
| 13 | 96296410 |
| 14 | 409573584 |
| 15 | 1741574006 |
| 16 | 7403616923 |
| 17 | 31466106703 |
| 18 | 133704121665 |
| 19 | 568008916093 |
| 20 | 2412570019447 |
| 21 | 10245302874071 |
| 22 | 43500597657111 |
| 23 | 184670002546295 |
| 24 | 783850164628721 |
| 25 | 3326671128027805 |
| 26 | 14116630429874265 |