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) |
|---|---|
| 3 | 1 |
| 4 | 3 |
| 5 | 9 |
| 6 | 29 |
| 7 | 98 |
| 8 | 343 |
| 9 | 1230 |
| 10 | 4489 |
| 11 | 16599 |
| 12 | 61997 |
| 13 | 233389 |
| 14 | 884170 |
| 15 | 3366951 |
| 16 | 12876702 |
| 17 | 49424984 |
| 18 | 190297064 |
| 19 | 734644291 |
| 20 | 2842707951 |
| 21 | 11022366544 |
| 22 | 42815701060 |
| 23 | 166583279325 |
| 24 | 649063995030 |
| 25 | 2532267577126 |
| 26 | 9891097066760 |
| 27 | 38676401680776 |
| 28 | 151381995733542 |
| 29 | 593053313030007 |