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 | 1 |
| 2 | 3 |
| 3 | 7 |
| 4 | 20 |
| 5 | 63 |
| 6 | 232 |
| 7 | 944 |
| 8 | 4158 |
| 9 | 19236 |
| 10 | 91794 |
| 11 | 446311 |
| 12 | 2194569 |
| 13 | 10863768 |
| 14 | 53995350 |
| 15 | 269013587 |
| 16 | 1342192961 |
| 17 | 6702368648 |
| 18 | 33486112079 |
| 19 | 167353481065 |
| 20 | 836536395240 |
| 21 | 4181989400979 |
| 22 | 20907870188551 |
| 23 | 104533122311131 |
| 24 | 522646929294281 |
| 25 | 2613178606952285 |