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 | 8 |
| 2 | 34 |
| 3 | 150 |
| 4 | 668 |
| 5 | 2986 |
| 6 | 13362 |
| 7 | 59816 |
| 8 | 267802 |
| 9 | 1199022 |
| 10 | 5368412 |
| 11 | 24036226 |
| 12 | 107618586 |
| 13 | 481846232 |
| 14 | 2157395218 |
| 15 | 9659418342 |
| 16 | 43248619100 |
| 17 | 193639305850 |
| 18 | 866991400098 |
| 19 | 3881825980040 |
| 20 | 17380302665002 |
| 21 | 77817738944382 |