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) |
|---|---|
| 1 | 1 |
| 2 | 15 |
| 3 | 86 |
| 4 | 587 |
| 5 | 3815 |
| 6 | 25131 |
| 7 | 164916 |
| 8 | 1083375 |
| 9 | 7114906 |
| 10 | 46729709 |
| 11 | 306907879 |
| 12 | 2015697730 |
| 13 | 13238601897 |
| 14 | 86947883732 |
| 15 | 571052268590 |
| 16 | 3750530654213 |
| 17 | 24632561409541 |
| 18 | 161780595565168 |
| 19 | 1062535099406293 |
| 20 | 6978468794154813 |