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) |
|---|---|
| 2 | 1 |
| 3 | 1 |
| 4 | 3 |
| 5 | 11 |
| 6 | 46 |
| 7 | 210 |
| 8 | 1021 |
| 9 | 5202 |
| 10 | 27477 |
| 11 | 149324 |
| 12 | 830357 |
| 13 | 4705386 |
| 14 | 27087106 |
| 15 | 158019030 |
| 16 | 932390694 |
| 17 | 5555902302 |
| 18 | 33391080001 |
| 19 | 202196156448 |
| 20 | 1232550473918 |
| 21 | 7558030268270 |
| 22 | 46592437224093 |
| 23 | 288599067239678 |
| 24 | 1795348952256896 |