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 | 2 |
| 4 | 10 |
| 5 | 36 |
| 6 | 150 |
| 7 | 602 |
| 8 | 2485 |
| 9 | 10256 |
| 10 | 42687 |
| 11 | 178300 |
| 12 | 747912 |
| 13 | 3146936 |
| 14 | 13278707 |
| 15 | 56163758 |
| 16 | 238052050 |
| 17 | 1010857520 |
| 18 | 4299545769 |
| 19 | 18314436414 |
| 20 | 78115839734 |
| 21 | 333583225740 |
| 22 | 1426072211137 |
| 23 | 6102528959956 |
| 24 | 26138050436822 |
| 25 | 112046904456640 |
| 26 | 480686415837200 |
| 27 | 2063641522153406 |
| 28 | 8865329237958042 |
| 29 | 38108667849379540 |