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) |
|---|---|
| 2 | 1 |
| 3 | 1 |
| 4 | 5 |
| 5 | 17 |
| 6 | 53 |
| 7 | 161 |
| 8 | 477 |
| 9 | 1393 |
| 10 | 4033 |
| 11 | 11617 |
| 12 | 33365 |
| 13 | 95681 |
| 14 | 274209 |
| 15 | 785793 |
| 16 | 2252509 |
| 17 | 6460433 |
| 18 | 18542169 |
| 19 | 53260481 |
| 20 | 153115765 |
| 21 | 440572993 |
| 22 | 1268830877 |
| 23 | 3657435745 |
| 24 | 10551936125 |
| 25 | 30469329025 |
| 26 | 88056216233 |
| 27 | 254690980449 |