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 | 5 |
| 3 | 39 |
| 4 | 209 |
| 5 | 2857 |
| 6 | 11883 |
| 7 | 233057 |
| 8 | 2632787 |
| 9 | 13468239 |
| 10 | 13739939 |
| 11 | 433545709 |
| 12 | 7488194853 |
| 13 | 281072414761 |
| 14 | 284780929571 |
| 15 | 12393920563953 |
| 16 | 288249495707519 |
| 17 | 2038704876507433 |
| 18 | 2058454144222533 |
| 19 | 2077126179153173 |
| 20 | 60750140156034617 |