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) |
|---|---|
| 8 | 1 |
| 9 | 9 |
| 10 | 45 |
| 11 | 165 |
| 12 | 495 |
| 13 | 1287 |
| 14 | 3003 |
| 15 | 6435 |
| 16 | 12870 |
| 17 | 24310 |
| 18 | 43758 |
| 19 | 75582 |
| 20 | 125970 |
| 21 | 203490 |
| 22 | 319770 |
| 23 | 490314 |
| 24 | 735471 |
| 25 | 1081575 |
| 26 | 1562275 |
| 27 | 2220075 |
| 28 | 3108105 |
| 29 | 4292145 |
| 30 | 5852925 |
| 31 | 7888725 |
| 32 | 10518300 |
| 33 | 13884156 |
| 34 | 18156204 |
| 35 | 23535820 |
| 36 | 30260340 |
| 37 | 38608020 |
| 38 | 48903492 |
| 39 | 61523748 |
| 40 | 76904685 |