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 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 15 |
| 5 | 50 |
| 6 | 178 |
| 7 | 663 |
| 8 | 2552 |
| 9 | 10071 |
| 10 | 40528 |
| 11 | 165682 |
| 12 | 686151 |
| 13 | 2872576 |
| 14 | 12137278 |
| 15 | 51690255 |
| 16 | 221657999 |
| 17 | 956265050 |
| 18 | 4147533262 |
| 19 | 18074429421 |
| 20 | 79102157060 |
| 21 | 347519074010 |
| 22 | 1532070899412 |
| 23 | 6775687911920 |
| 24 | 30052744139440 |
| 25 | 133649573395725 |
| 26 | 595816470717728 |