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) |
|---|---|
| 0 | 1 |
| 1 | 5 |
| 2 | 19 |
| 3 | 66 |
| 4 | 221 |
| 5 | 728 |
| 6 | 2380 |
| 7 | 7753 |
| 8 | 25213 |
| 9 | 81927 |
| 10 | 266110 |
| 11 | 864201 |
| 12 | 2806272 |
| 13 | 9112264 |
| 14 | 29587889 |
| 15 | 96072133 |
| 16 | 311945595 |
| 17 | 1012883066 |
| 18 | 3288813893 |
| 19 | 10678716664 |
| 20 | 34673583028 |
| 21 | 112584429049 |
| 22 | 365559363741 |
| 23 | 1186963827439 |
| 24 | 3854047383798 |
| 25 | 12514013318097 |
| 26 | 40632746115136 |