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 | 3 |
| 2 | 9 |
| 3 | 30 |
| 4 | 114 |
| 5 | 445 |
| 6 | 1821 |
| 7 | 7671 |
| 8 | 33118 |
| 9 | 145713 |
| 10 | 650133 |
| 11 | 2934858 |
| 12 | 13375865 |
| 13 | 61444585 |
| 14 | 284140656 |
| 15 | 1321453490 |
| 16 | 6175961983 |
| 17 | 28988040005 |
| 18 | 136575061279 |
| 19 | 645620925545 |
| 20 | 3061129684411 |
| 21 | 14552990145243 |
| 22 | 69354801708586 |
| 23 | 331251325552977 |
| 24 | 1585299642009257 |
| 25 | 7600886353341754 |
| 26 | 36504944044424979 |