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) |
|---|---|
| 2 | 1 |
| 3 | 8 |
| 4 | 52 |
| 5 | 224 |
| 6 | 987 |
| 7 | 3980 |
| 8 | 16057 |
| 9 | 63732 |
| 10 | 252424 |
| 11 | 996332 |
| 12 | 3927977 |
| 13 | 15471622 |
| 14 | 60915547 |
| 15 | 239794516 |
| 16 | 943946193 |
| 17 | 3716205884 |
| 18 | 14632901696 |
| 19 | 57631689776 |
| 20 | 227042423404 |
| 21 | 894698122022 |
| 22 | 3526753844436 |
| 23 | 13906101471344 |
| 24 | 54848887043366 |
| 25 | 216402159510134 |
| 26 | 854053133294062 |
| 27 | 3371593602442500 |