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 | 18 |
| 5 | 59 |
| 6 | 198 |
| 7 | 690 |
| 8 | 2450 |
| 9 | 8878 |
| 10 | 32632 |
| 11 | 121518 |
| 12 | 457262 |
| 13 | 1736526 |
| 14 | 6646340 |
| 15 | 25613086 |
| 16 | 99298674 |
| 17 | 387021728 |
| 18 | 1515594560 |
| 19 | 5960406102 |
| 20 | 23530528512 |
| 21 | 93216984177 |
| 22 | 370450977206 |
| 23 | 1476458287082 |
| 24 | 5900150928510 |
| 25 | 23635544130948 |