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 | 6 |
| 1 | 6 |
| 2 | 13 |
| 3 | 41 |
| 4 | 167 |
| 5 | 839 |
| 6 | 5039 |
| 7 | 35279 |
| 8 | 282239 |
| 9 | 2540159 |
| 10 | 25401599 |
| 11 | 279417599 |
| 12 | 3353011199 |
| 13 | 43589145599 |
| 14 | 610248038399 |
| 15 | 9153720575999 |
| 16 | 146459529215999 |
| 17 | 2489811996671999 |
| 18 | 44816615940095999 |
| 19 | 851515702861823999 |
| 20 | 17030314057236479999 |
| 21 | 357636595201966079999 |