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 | 3 |
| 1 | 69 |
| 2 | 310 |
| 3 | 1017 |
| 4 | 36745 |
| 5 | 214369 |
| 6 | 966652 |
| 7 | 11159821 |
| 8 | 74039764 |
| 9 | 550021544 |
| 10 | 4481549430 |
| 11 | 16543857917 |
| 12 | 87205978613 |
| 13 | 476981856953 |
| 14 | 30989048525367 |
| 15 | 203786458494160 |
| 16 | 711639924282497 |
| 17 | 3174772986229899 |
| 18 | 29814569078896025 |
| 19 | 100158574806804154 |