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 | 4 |
| 3 | 9 |
| 4 | 26 |
| 5 | 70 |
| 6 | 197 |
| 7 | 553 |
| 8 | 1570 |
| 9 | 4476 |
| 10 | 12827 |
| 11 | 36894 |
| 12 | 106471 |
| 13 | 308113 |
| 14 | 893804 |
| 15 | 2598313 |
| 16 | 7567466 |
| 17 | 22076404 |
| 18 | 64498427 |
| 19 | 188689684 |
| 20 | 552675365 |
| 21 | 1620567763 |
| 22 | 4756614062 |
| 23 | 13974168190 |
| 24 | 41088418151 |
| 25 | 120906613075 |
| 26 | 356035078102 |