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 | 1 |
| 2 | 9 |
| 3 | 45 |
| 4 | 165 |
| 5 | 496 |
| 6 | 1297 |
| 7 | 3058 |
| 8 | 6655 |
| 9 | 13586 |
| 10 | 26323 |
| 11 | 48829 |
| 12 | 87308 |
| 13 | 151282 |
| 14 | 255125 |
| 15 | 420234 |
| 16 | 678086 |
| 17 | 1074525 |
| 18 | 1675754 |
| 19 | 2576688 |
| 20 | 3912574 |
| 21 | 5875129 |
| 22 | 8734923 |
| 23 | 12872391 |
| 24 | 18820765 |
| 25 | 27325469 |
| 26 | 39426248 |
| 27 | 56570687 |
| 28 | 80771068 |
| 29 | 114821057 |
| 30 | 162594985 |