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) |
|---|---|
| 1 | 15 |
| 2 | 225 |
| 3 | 2111 |
| 4 | 14123 |
| 5 | 74040 |
| 6 | 323394 |
| 7 | 1226491 |
| 8 | 4157102 |
| 9 | 12856218 |
| 10 | 36834899 |
| 11 | 98904313 |
| 12 | 251078009 |
| 13 | 606789828 |
| 14 | 1403779390 |
| 15 | 3122765753 |
| 16 | 6704628063 |
| 17 | 13936852281 |
| 18 | 28123662137 |
| 19 | 55220811463 |
| 20 | 105715542647 |
| 21 | 197678421680 |