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 | 2 |
| 3 | 9 |
| 4 | 32 |
| 5 | 130 |
| 6 | 516 |
| 7 | 2107 |
| 8 | 8632 |
| 9 | 35703 |
| 10 | 148390 |
| 11 | 619850 |
| 12 | 2598960 |
| 13 | 10933507 |
| 14 | 46124274 |
| 15 | 195055005 |
| 16 | 826617216 |
| 17 | 3509650697 |
| 18 | 14926011714 |
| 19 | 63572290247 |
| 20 | 271125967840 |
| 21 | 1157705297385 |
| 22 | 4948808238110 |
| 23 | 21175676836110 |
| 24 | 90692557152240 |
| 25 | 388751132082600 |
| 26 | 1667665994149376 |
| 27 | 7159105163384127 |
| 28 | 30753762496639504 |