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 | 3 |
| 2 | 19 |
| 3 | 159 |
| 4 | 1565 |
| 5 | 17022 |
| 6 | 197928 |
| 7 | 2413494 |
| 8 | 30490089 |
| 9 | 395828145 |
| 10 | 5250493688 |
| 11 | 70863932052 |
| 12 | 970121212741 |
| 13 | 13439019867456 |
| 14 | 188038364992270 |
| 15 | 2653560128625570 |
| 16 | 37723174042204665 |
| 17 | 539726553801797610 |
| 18 | 7765849268430279390 |