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 | 19 |
| 2 | 218 |
| 3 | 1955 |
| 4 | 15086 |
| 5 | 105102 |
| 6 | 679764 |
| 7 | 4154403 |
| 8 | 24281510 |
| 9 | 136887322 |
| 10 | 749032492 |
| 11 | 3997228430 |
| 12 | 20880823820 |
| 13 | 107088473660 |
| 14 | 540472210728 |
| 15 | 2689562860323 |
| 16 | 13217998697430 |
| 17 | 64240718824930 |
| 18 | 309108505173820 |