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 | 4 |
| 2 | 16 |
| 3 | 63 |
| 4 | 248 |
| 5 | 976 |
| 6 | 3841 |
| 7 | 15116 |
| 8 | 59488 |
| 9 | 234111 |
| 10 | 921328 |
| 11 | 3625824 |
| 12 | 14269185 |
| 13 | 56155412 |
| 14 | 220995824 |
| 15 | 869714111 |
| 16 | 3422701032 |
| 17 | 13469808304 |
| 18 | 53009519105 |
| 19 | 208615375388 |
| 20 | 820991693248 |
| 21 | 3230957253887 |
| 22 | 12715213640160 |
| 23 | 50039862867392 |