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 | 2 |
| 3 | 4 |
| 4 | 8 |
| 5 | 26 |
| 6 | 66 |
| 7 | 276 |
| 8 | 816 |
| 9 | 4050 |
| 10 | 13410 |
| 11 | 75780 |
| 12 | 274680 |
| 13 | 1723050 |
| 14 | 6735330 |
| 15 | 46104660 |
| 16 | 192296160 |
| 17 | 1418802210 |
| 18 | 6264006210 |
| 19 | 49355252100 |
| 20 | 229233450600 |
| 21 | 1914861598650 |
| 22 | 9309854203650 |
| 23 | 81969299111700 |
| 24 | 415483465597200 |
| 25 | 3837397323409650 |
| 26 | 20209910950879650 |