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 | 0 |
| 1 | 1 |
| 2 | 7 |
| 3 | 34 |
| 4 | 138 |
| 5 | 501 |
| 6 | 1683 |
| 7 | 5336 |
| 8 | 16172 |
| 9 | 47264 |
| 10 | 134048 |
| 11 | 370688 |
| 12 | 1003136 |
| 13 | 2664192 |
| 14 | 6960384 |
| 15 | 17922048 |
| 16 | 45552640 |
| 17 | 114442240 |
| 18 | 284508160 |
| 19 | 700579840 |
| 20 | 1710161920 |
| 21 | 4141416448 |
| 22 | 9955639296 |
| 23 | 23770693632 |
| 24 | 56400543744 |
| 25 | 133041225728 |