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 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 9 |
| 5 | 21 |
| 6 | 55 |
| 7 | 146 |
| 8 | 415 |
| 9 | 1212 |
| 10 | 3653 |
| 11 | 11246 |
| 12 | 35346 |
| 13 | 112750 |
| 14 | 364714 |
| 15 | 1193202 |
| 16 | 3943557 |
| 17 | 13148575 |
| 18 | 44186841 |
| 19 | 149536376 |
| 20 | 509270554 |
| 21 | 1744342614 |
| 22 | 6005869285 |
| 23 | 20777091355 |
| 24 | 72192026878 |
| 25 | 251848377631 |
| 26 | 881865312582 |
| 27 | 3098564357293 |
| 28 | 10922162622233 |
| 29 | 38614641384893 |