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) |
|---|---|
| 5 | 1 |
| 6 | 5 |
| 7 | 20 |
| 8 | 70 |
| 9 | 230 |
| 10 | 721 |
| 11 | 2200 |
| 12 | 6575 |
| 13 | 19385 |
| 14 | 56575 |
| 15 | 163952 |
| 16 | 472645 |
| 17 | 1357550 |
| 18 | 3888820 |
| 19 | 11119325 |
| 20 | 31753269 |
| 21 | 90603650 |
| 22 | 258401245 |
| 23 | 736796675 |
| 24 | 2100818555 |
| 25 | 5990757124 |
| 26 | 17087376630 |
| 27 | 48753542665 |
| 28 | 139155765455 |
| 29 | 397356692275 |
| 30 | 1135163887190 |
| 31 | 3244482184720 |
| 32 | 9277856948255 |