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 | 5 |
| 3 | 13 |
| 4 | 34 |
| 5 | 90 |
| 6 | 240 |
| 7 | 643 |
| 8 | 1729 |
| 9 | 4662 |
| 10 | 12597 |
| 11 | 34095 |
| 12 | 92406 |
| 13 | 250719 |
| 14 | 680877 |
| 15 | 1850457 |
| 16 | 5032296 |
| 17 | 13692674 |
| 18 | 37274438 |
| 19 | 101509476 |
| 20 | 276535824 |
| 21 | 753574253 |
| 22 | 2054064713 |
| 23 | 5600176231 |
| 24 | 15271331416 |
| 25 | 41651397245 |
| 26 | 113618996429 |
| 27 | 309979833301 |
| 28 | 845805408448 |
| 29 | 2308108658854 |
| 30 | 6299205562846 |