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 | 6 |
| 3 | 39 |
| 4 | 262 |
| 5 | 1791 |
| 6 | 12372 |
| 7 | 86052 |
| 8 | 601374 |
| 9 | 4217151 |
| 10 | 29648766 |
| 11 | 208855791 |
| 12 | 1473509736 |
| 13 | 10408539844 |
| 14 | 73596075552 |
| 15 | 520797997464 |
| 16 | 3687846866382 |
| 17 | 26128671296127 |
| 18 | 185209915856802 |
| 19 | 1313356295909877 |
| 20 | 9316374980571702 |
| 21 | 66105343198654407 |
| 22 | 469174119885678972 |