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 | 1 |
| 1 | 2 |
| 2 | 9 |
| 3 | 36 |
| 4 | 154 |
| 5 | 644 |
| 6 | 2744 |
| 7 | 11608 |
| 8 | 49267 |
| 9 | 208610 |
| 10 | 882963 |
| 11 | 3731640 |
| 12 | 15754327 |
| 13 | 66426946 |
| 14 | 279766063 |
| 15 | 1176920484 |
| 16 | 4945739292 |
| 17 | 20761707824 |
| 18 | 87069433162 |
| 19 | 364802647912 |
| 20 | 1527072152856 |
| 21 | 6386873581244 |
| 22 | 26690795165394 |
| 23 | 111453873957936 |
| 24 | 465055114353616 |
| 25 | 1939114409985956 |