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 | 6 |
| 4 | 17 |
| 5 | 45 |
| 6 | 120 |
| 7 | 324 |
| 8 | 873 |
| 9 | 2349 |
| 10 | 6322 |
| 11 | 17018 |
| 12 | 45809 |
| 13 | 123305 |
| 14 | 331904 |
| 15 | 893400 |
| 16 | 2404801 |
| 17 | 6473097 |
| 18 | 17423890 |
| 19 | 46900574 |
| 20 | 126244129 |
| 21 | 339816309 |
| 22 | 914696984 |
| 23 | 2462126012 |
| 24 | 6627401865 |
| 25 | 17839239445 |
| 26 | 48018585634 |
| 27 | 129253524146 |
| 28 | 347916817697 |
| 29 | 936501444241 |
| 30 | 2520817938240 |