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 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 14 |
| 6 | 43 |
| 7 | 140 |
| 8 | 474 |
| 9 | 1650 |
| 10 | 5863 |
| 11 | 21170 |
| 12 | 77441 |
| 13 | 286372 |
| 14 | 1068790 |
| 15 | 4020704 |
| 16 | 15230470 |
| 17 | 58044354 |
| 18 | 222401745 |
| 19 | 856235030 |
| 20 | 3310615055 |
| 21 | 12849946406 |
| 22 | 50051007940 |
| 23 | 195571906140 |
| 24 | 766413504375 |
| 25 | 3011469930300 |
| 26 | 11862075827007 |
| 27 | 46830440626612 |
| 28 | 185271557066226 |