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 | 9 |
| 2 | 77 |
| 3 | 661 |
| 4 | 5673 |
| 5 | 48689 |
| 6 | 417877 |
| 7 | 3586461 |
| 8 | 30781073 |
| 9 | 264180889 |
| 10 | 2267352477 |
| 11 | 19459724261 |
| 12 | 167014556473 |
| 13 | 1433415073089 |
| 14 | 12302393367077 |
| 15 | 105586222302061 |
| 16 | 906201745251873 |
| 17 | 7777545073525289 |
| 18 | 66751369314461677 |
| 19 | 572898679883319861 |
| 20 | 4916946285638867273 |