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 | 4 |
| 5 | 11 |
| 6 | 35 |
| 7 | 104 |
| 8 | 319 |
| 9 | 951 |
| 10 | 2862 |
| 11 | 8516 |
| 12 | 25369 |
| 13 | 75167 |
| 14 | 222529 |
| 15 | 656961 |
| 16 | 1937393 |
| 17 | 5704426 |
| 18 | 16781247 |
| 19 | 49320800 |
| 20 | 144866243 |
| 21 | 425263010 |
| 22 | 1247877578 |
| 23 | 3660478408 |
| 24 | 10734834603 |
| 25 | 31475111515 |
| 26 | 92273758477 |
| 27 | 270486112046 |
| 28 | 792836030163 |
| 29 | 2323835125879 |
| 30 | 6811162237825 |