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 | 3 |
| 2 | 9 |
| 3 | 25 |
| 4 | 67 |
| 5 | 177 |
| 6 | 465 |
| 7 | 1219 |
| 8 | 3193 |
| 9 | 8361 |
| 10 | 21891 |
| 11 | 57313 |
| 12 | 150049 |
| 13 | 392835 |
| 14 | 1028457 |
| 15 | 2692537 |
| 16 | 7049155 |
| 17 | 18454929 |
| 18 | 48315633 |
| 19 | 126491971 |
| 20 | 331160281 |
| 21 | 866988873 |
| 22 | 2269806339 |
| 23 | 5942430145 |
| 24 | 15557484097 |
| 25 | 40730022147 |
| 26 | 106632582345 |
| 27 | 279167724889 |
| 28 | 730870592323 |
| 29 | 1913444052081 |