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 | 22 |
| 3 | 130 |
| 4 | 790 |
| 5 | 4870 |
| 6 | 30274 |
| 7 | 189202 |
| 8 | 1186702 |
| 9 | 7461982 |
| 10 | 47007034 |
| 11 | 296527162 |
| 12 | 1872479350 |
| 13 | 11833642006 |
| 14 | 74833075570 |
| 15 | 473463268642 |
| 16 | 2996771766046 |
| 17 | 18974162475598 |
| 18 | 120167557286314 |
| 19 | 761214481604554 |
| 20 | 4822871486667526 |
| 21 | 30561172252753030 |
| 22 | 193682023673424226 |
| 23 | 1227594333811376050 |
| 24 | 7781431761074125486 |