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 | 9 |
| 3 | 22 |
| 4 | 142 |
| 5 | 1146 |
| 6 | 7456 |
| 7 | 55663 |
| 8 | 400028 |
| 9 | 2906875 |
| 10 | 21162204 |
| 11 | 153677233 |
| 12 | 1117612488 |
| 13 | 8123629685 |
| 14 | 59057261422 |
| 15 | 429317113075 |
| 16 | 3120977422852 |
| 17 | 22688267741133 |
| 18 | 164934718709179 |
| 19 | 1199012026918226 |
| 20 | 8716348960310287 |
| 21 | 63364478025520501 |