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 | 1 |
| 2 | 4 |
| 3 | 22 |
| 4 | 156 |
| 5 | 1193 |
| 6 | 9748 |
| 7 | 82916 |
| 8 | 727088 |
| 9 | 6524084 |
| 10 | 59620732 |
| 11 | 552970626 |
| 12 | 5191935808 |
| 13 | 49252903050 |
| 14 | 471358286352 |
| 15 | 4545310993994 |
| 16 | 44121116086052 |
| 17 | 430777978197156 |
| 18 | 4227634212037728 |
| 19 | 41680927531643928 |
| 20 | 412638233333973820 |
| 21 | 4100336181515969163 |
| 22 | 40882494461218775272 |