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 | 6 |
| 3 | 21 |
| 4 | 71 |
| 5 | 216 |
| 6 | 657 |
| 7 | 1907 |
| 8 | 5507 |
| 9 | 15522 |
| 10 | 43352 |
| 11 | 119140 |
| 12 | 323946 |
| 13 | 869476 |
| 14 | 2308071 |
| 15 | 6056581 |
| 16 | 15724170 |
| 17 | 40393693 |
| 18 | 102736274 |
| 19 | 258790004 |
| 20 | 645968054 |
| 21 | 1598460229 |
| 22 | 3923114261 |
| 23 | 9554122089 |
| 24 | 23098084695 |
| 25 | 55458417125 |
| 26 | 132293945737 |
| 27 | 313657570114 |