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 | 22 |
| 5 | 87 |
| 6 | 354 |
| 7 | 1465 |
| 8 | 6154 |
| 9 | 26223 |
| 10 | 113236 |
| 11 | 494870 |
| 12 | 2185700 |
| 13 | 9743281 |
| 14 | 43784838 |
| 15 | 198156234 |
| 16 | 902374498 |
| 17 | 4131895035 |
| 18 | 19012201080 |
| 19 | 87864535600 |
| 20 | 407664831856 |
| 21 | 1898184887679 |
| 22 | 8867042353912 |
| 23 | 41543375724751 |
| 24 | 195164372948152 |
| 25 | 919138464708907 |
| 26 | 4338701289961694 |
| 27 | 20524046955770940 |