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 | 2 |
| 3 | 6 |
| 4 | 21 |
| 5 | 73 |
| 6 | 247 |
| 7 | 821 |
| 8 | 2704 |
| 9 | 8868 |
| 10 | 29030 |
| 11 | 94960 |
| 12 | 310531 |
| 13 | 1015359 |
| 14 | 3319829 |
| 15 | 10854379 |
| 16 | 35488838 |
| 17 | 116031978 |
| 18 | 379370276 |
| 19 | 1240362982 |
| 20 | 4055405209 |
| 21 | 13259272613 |
| 22 | 43351600979 |
| 23 | 141739396705 |
| 24 | 463421329340 |
| 25 | 1515170329456 |
| 26 | 4953896123490 |
| 27 | 16196916164572 |
| 28 | 52956316947055 |
| 29 | 173142311541835 |