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 | 1 |
| 1 | 3 |
| 2 | 20 |
| 3 | 143 |
| 4 | 1442 |
| 5 | 14377 |
| 6 | 143071 |
| 7 | 1418854 |
| 8 | 14255667 |
| 9 | 145674808 |
| 10 | 1492609148 |
| 11 | 15091199357 |
| 12 | 149121303586 |
| 13 | 1443278000870 |
| 14 | 13770853279685 |
| 15 | 130660965862333 |
| 16 | 1245219117260664 |
| 17 | 12024696404768025 |
| 18 | 118226055080025491 |
| 19 | 1183229962059381238 |
| 20 | 12005034444292997294 |