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 | 0 |
| 2 | 34 |
| 3 | 18 |
| 4 | 213 |
| 5 | 1574 |
| 6 | 11202 |
| 7 | 65218 |
| 8 | 479206 |
| 9 | 3481050 |
| 10 | 24695892 |
| 11 | 177272585 |
| 12 | 1292781132 |
| 13 | 9346339114 |
| 14 | 67597407637 |
| 15 | 490930663188 |
| 16 | 3562917786488 |
| 17 | 25842902976432 |
| 18 | 187580825378770 |
| 19 | 1361838171557890 |
| 20 | 9885195460409937 |