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 | 1 |
| 2 | 6 |
| 3 | 27 |
| 4 | 119 |
| 5 | 533 |
| 6 | 2402 |
| 7 | 10829 |
| 8 | 48804 |
| 9 | 219925 |
| 10 | 991044 |
| 11 | 4465957 |
| 12 | 20125051 |
| 13 | 90690002 |
| 14 | 408678475 |
| 15 | 1841637299 |
| 16 | 8299012941 |
| 17 | 37398034921 |
| 18 | 168527634148 |
| 19 | 759439995404 |
| 20 | 3422282105232 |
| 21 | 15421909405056 |
| 22 | 69496108849357 |
| 23 | 313171930813206 |
| 24 | 1411253951813003 |
| 25 | 6359566489040219 |