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 | 5 |
| 2 | 21 |
| 3 | 91 |
| 4 | 433 |
| 5 | 2307 |
| 6 | 13804 |
| 7 | 92433 |
| 8 | 688611 |
| 9 | 5670713 |
| 10 | 51291468 |
| 11 | 506502769 |
| 12 | 5430460072 |
| 13 | 62894124926 |
| 14 | 783259655434 |
| 15 | 10445143907067 |
| 16 | 148592182641759 |
| 17 | 2247301621235992 |
| 18 | 36021020633412788 |
| 19 | 610161098104988668 |