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 | 4 |
| 2 | 15 |
| 3 | 50 |
| 4 | 157 |
| 5 | 480 |
| 6 | 1451 |
| 7 | 4366 |
| 8 | 13113 |
| 9 | 39356 |
| 10 | 118087 |
| 11 | 354282 |
| 12 | 1062869 |
| 13 | 3188632 |
| 14 | 9565923 |
| 15 | 28697798 |
| 16 | 86093425 |
| 17 | 258280308 |
| 18 | 774840959 |
| 19 | 2324522914 |
| 20 | 6973568781 |
| 21 | 20920706384 |
| 22 | 62762119195 |
| 23 | 188286357630 |
| 24 | 564859072937 |
| 25 | 1694577218860 |