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 | 2 |
| 3 | 6 |
| 4 | 25 |
| 5 | 113 |
| 6 | 548 |
| 7 | 2770 |
| 8 | 14426 |
| 9 | 76851 |
| 10 | 416848 |
| 11 | 2294224 |
| 12 | 12780394 |
| 13 | 71924647 |
| 14 | 408310668 |
| 15 | 2335443077 |
| 16 | 13446130438 |
| 17 | 77863375126 |
| 18 | 453203435319 |
| 19 | 2649957419351 |
| 20 | 15558520126830 |
| 21 | 91687179000949 |
| 22 | 542139459641933 |
| 23 | 3215484006733932 |
| 24 | 19125017153077911 |