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 | 0 |
| 1 | 6 |
| 2 | 46 |
| 3 | 339 |
| 4 | 2553 |
| 5 | 19723 |
| 6 | 155805 |
| 7 | 1253931 |
| 8 | 10249096 |
| 9 | 84864051 |
| 10 | 710429304 |
| 11 | 6003238901 |
| 12 | 51140131770 |
| 13 | 438729741450 |
| 14 | 3787208722815 |
| 15 | 32871470376123 |
| 16 | 286706337100656 |
| 17 | 2511620756461504 |
| 18 | 22089299382478728 |
| 19 | 194966351598215340 |
| 20 | 1726424465382128205 |