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 | 3 |
| 3 | 10 |
| 4 | 36 |
| 5 | 121 |
| 6 | 447 |
| 7 | 1699 |
| 8 | 6589 |
| 9 | 25914 |
| 10 | 103633 |
| 11 | 419421 |
| 12 | 1714463 |
| 13 | 7068285 |
| 14 | 29361629 |
| 15 | 122764876 |
| 16 | 516245009 |
| 17 | 2181957489 |
| 18 | 9264275600 |
| 19 | 39495666700 |
| 20 | 169000837410 |
| 21 | 725574719515 |
| 22 | 3124648750706 |
| 23 | 13493792787415 |
| 24 | 58422790497226 |
| 25 | 253547380435914 |
| 26 | 1102776319943605 |