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 | 35 |
| 5 | 99 |
| 6 | 295 |
| 7 | 920 |
| 8 | 2975 |
| 9 | 9892 |
| 10 | 33605 |
| 11 | 116104 |
| 12 | 406615 |
| 13 | 1440026 |
| 14 | 5147877 |
| 15 | 18550573 |
| 16 | 67310939 |
| 17 | 245716095 |
| 18 | 901759951 |
| 19 | 3325066997 |
| 20 | 12312494463 |
| 21 | 45766188949 |
| 22 | 170702447075 |
| 23 | 638698318851 |
| 24 | 2396598337951 |
| 25 | 9016444758503 |
| 26 | 34003644251207 |
| 27 | 128524394659915 |