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 | 2 |
| 2 | 2 |
| 3 | 6 |
| 4 | 22 |
| 5 | 54 |
| 6 | 102 |
| 7 | 214 |
| 8 | 582 |
| 9 | 1590 |
| 10 | 3814 |
| 11 | 8662 |
| 12 | 20934 |
| 13 | 53942 |
| 14 | 137190 |
| 15 | 335574 |
| 16 | 815942 |
| 17 | 2032694 |
| 18 | 5139942 |
| 19 | 12902614 |
| 20 | 32059846 |
| 21 | 79807158 |
| 22 | 200325350 |
| 23 | 504502230 |
| 24 | 1267146054 |
| 25 | 3176193590 |
| 26 | 7975495910 |
| 27 | 20082938838 |
| 28 | 50611676614 |
| 29 | 127466481334 |