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 | 14 |
| 3 | 80 |
| 4 | 345 |
| 5 | 1336 |
| 6 | 5074 |
| 7 | 18404 |
| 8 | 64460 |
| 9 | 220276 |
| 10 | 736242 |
| 11 | 2415128 |
| 12 | 7798043 |
| 13 | 24833160 |
| 14 | 78131242 |
| 15 | 243211412 |
| 16 | 749926963 |
| 17 | 2292771088 |
| 18 | 6956262660 |
| 19 | 20959406680 |
| 20 | 62753991192 |
| 21 | 186809711448 |
| 22 | 553172044548 |
| 23 | 1630068765840 |
| 24 | 4781871397429 |
| 25 | 13969460520764 |