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 | 1 |
| 2 | 2 |
| 3 | 12 |
| 4 | 48 |
| 5 | 457 |
| 6 | 1027 |
| 7 | 6190 |
| 8 | 14652 |
| 9 | 40852 |
| 10 | 71601 |
| 11 | 223637 |
| 12 | 325661 |
| 13 | 847984 |
| 14 | 1269433 |
| 15 | 2053303 |
| 16 | 3157887 |
| 17 | 6638971 |
| 18 | 8490949 |
| 19 | 16421392 |
| 20 | 21323264 |
| 21 | 30639928 |