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 | 3 |
| 3 | 16 |
| 4 | 38 |
| 5 | 128 |
| 6 | 324 |
| 7 | 1068 |
| 8 | 2569 |
| 9 | 8381 |
| 10 | 20457 |
| 11 | 58174 |
| 12 | 148059 |
| 13 | 441493 |
| 14 | 916146 |
| 15 | 3722968 |
| 16 | 8407790 |
| 17 | 23909586 |
| 18 | 64576509 |
| 19 | 178009925 |
| 20 | 466027279 |
| 21 | 1409607602 |
| 22 | 3507905894 |
| 23 | 9694292108 |
| 24 | 25391646456 |
| 25 | 73838562312 |
| 26 | 191793924162 |
| 27 | 550333004128 |