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 | 13 |
| 3 | 63 |
| 4 | 324 |
| 5 | 1733 |
| 6 | 9541 |
| 7 | 53725 |
| 8 | 308085 |
| 9 | 1793528 |
| 10 | 10574165 |
| 11 | 63018105 |
| 12 | 379061652 |
| 13 | 2298508911 |
| 14 | 14035748542 |
| 15 | 86240951745 |
| 16 | 532812883413 |
| 17 | 3307967729867 |
| 18 | 20627845299471 |
| 19 | 129141164822496 |
| 20 | 811394148828087 |
| 21 | 5114638998643903 |
| 22 | 32336393838083539 |
| 23 | 205000199138736499 |
| 24 | 1302892014385402691 |