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 | 0 |
| 1 | 0 |
| 2 | 2 |
| 3 | 9 |
| 4 | 35 |
| 5 | 152 |
| 6 | 690 |
| 7 | 3476 |
| 8 | 18362 |
| 9 | 105507 |
| 10 | 633439 |
| 11 | 4077386 |
| 12 | 27317322 |
| 13 | 194202164 |
| 14 | 1431942154 |
| 15 | 11117639073 |
| 16 | 89255122863 |
| 17 | 750051307896 |
| 18 | 6500488706254 |
| 19 | 58693723144324 |
| 20 | 545325034579386 |
| 21 | 5258317906940219 |
| 22 | 52072378163037347 |
| 23 | 533479904210984930 |
| 24 | 5603461526474415150 |