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 | 24 |
| 2 | 114 |
| 3 | 426 |
| 4 | 1862 |
| 5 | 8194 |
| 6 | 36996 |
| 7 | 169088 |
| 8 | 781022 |
| 9 | 3635922 |
| 10 | 17034404 |
| 11 | 80221088 |
| 12 | 379426784 |
| 13 | 1801177896 |
| 14 | 8577255542 |
| 15 | 40956427846 |
| 16 | 196033612206 |
| 17 | 940269589202 |
| 18 | 4518417570036 |
| 19 | 21749390784152 |
| 20 | 104848429735272 |
| 21 | 506137481003552 |