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 | 1 |
| 2 | 3 |
| 3 | 11 |
| 4 | 44 |
| 5 | 179 |
| 6 | 730 |
| 7 | 2978 |
| 8 | 12149 |
| 9 | 49563 |
| 10 | 202197 |
| 11 | 824882 |
| 12 | 3365185 |
| 13 | 13728594 |
| 14 | 56007112 |
| 15 | 228486369 |
| 16 | 932131991 |
| 17 | 3802721591 |
| 18 | 15513566360 |
| 19 | 63289077427 |
| 20 | 258193843286 |
| 21 | 1053326473082 |
| 22 | 4297146069693 |
| 23 | 17530618299423 |