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 | 0 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 10 |
| 5 | 24 |
| 6 | 50 |
| 7 | 121 |
| 8 | 260 |
| 9 | 637 |
| 10 | 1400 |
| 11 | 3468 |
| 12 | 7752 |
| 13 | 19380 |
| 14 | 43890 |
| 15 | 110561 |
| 16 | 253000 |
| 17 | 641355 |
| 18 | 1480050 |
| 19 | 3771885 |
| 20 | 8765250 |
| 21 | 22439040 |
| 22 | 52451256 |
| 23 | 134796060 |
| 24 | 316663760 |
| 25 | 816540124 |
| 26 | 1926501200 |
| 27 | 4982228488 |
| 28 | 11798983280 |
| 29 | 30593078076 |
| 30 | 72690164850 |