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 | 0 |
| 2 | 15 |
| 3 | 46 |
| 4 | 305 |
| 5 | 1078 |
| 6 | 4948 |
| 7 | 18210 |
| 8 | 73277 |
| 9 | 270458 |
| 10 | 1026795 |
| 11 | 3757996 |
| 12 | 13847240 |
| 13 | 50155940 |
| 14 | 181596651 |
| 15 | 651546278 |
| 16 | 2331910405 |
| 17 | 8300115170 |
| 18 | 29460799452 |
| 19 | 104176325510 |
| 20 | 367430075801 |
| 21 | 1292287850546 |
| 22 | 4534933300095 |
| 23 | 15878737307224 |