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 | 2 |
| 2 | 6 |
| 3 | 17 |
| 4 | 50 |
| 5 | 147 |
| 6 | 435 |
| 7 | 1290 |
| 8 | 3834 |
| 9 | 11411 |
| 10 | 34001 |
| 11 | 101400 |
| 12 | 302615 |
| 13 | 903632 |
| 14 | 2699598 |
| 15 | 8068257 |
| 16 | 24121674 |
| 17 | 72137547 |
| 18 | 215786649 |
| 19 | 645629160 |
| 20 | 1932081885 |
| 21 | 5782851966 |
| 22 | 17311097568 |
| 23 | 51828203475 |
| 24 | 155188936431 |
| 25 | 464732722872 |