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) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 11 |
| 4 | 40 |
| 5 | 145 |
| 6 | 525 |
| 7 | 1900 |
| 8 | 6875 |
| 9 | 24875 |
| 10 | 90000 |
| 11 | 325625 |
| 12 | 1178125 |
| 13 | 4262500 |
| 14 | 15421875 |
| 15 | 55796875 |
| 16 | 201875000 |
| 17 | 730390625 |
| 18 | 2642578125 |
| 19 | 9560937500 |
| 20 | 34591796875 |
| 21 | 125154296875 |
| 22 | 452812500000 |
| 23 | 1638291015625 |
| 24 | 5927392578125 |
| 25 | 21445507812500 |
| 26 | 77590576171875 |