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 | 2 |
| 3 | 7 |
| 4 | 25 |
| 5 | 91 |
| 6 | 336 |
| 7 | 1254 |
| 8 | 4719 |
| 9 | 17875 |
| 10 | 68068 |
| 11 | 260338 |
| 12 | 999362 |
| 13 | 3848222 |
| 14 | 14858000 |
| 15 | 57500460 |
| 16 | 222981435 |
| 17 | 866262915 |
| 18 | 3370764540 |
| 19 | 13135064250 |
| 20 | 51250632510 |
| 21 | 200205672810 |
| 22 | 782920544640 |
| 23 | 3064665881940 |
| 24 | 12007086477750 |
| 25 | 47081501377326 |
| 26 | 184753963255176 |
| 27 | 725510446350004 |