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 | 2 |
| 2 | 6 |
| 3 | 30 |
| 4 | 146 |
| 5 | 42486 |
| 6 | 102966 |
| 7 | 597198 |
| 8 | 2847366 |
| 9 | 7998606 |
| 10 | 13133666 |
| 11 | 30478158 |
| 12 | 67622310 |
| 13 | 74476206 |
| 14 | 101258190 |
| 15 | 105161166 |
| 16 | 106364286 |
| 17 | 187605438 |
| 18 | 230000550 |
| 19 | 242915166 |
| 20 | 401913582 |
| 21 | 406756350 |
| 22 | 444314574 |
| 23 | 848205078 |
| 24 | 899715894 |
| 25 | 1508418054 |
| 26 | 1575220350 |
| 27 | 1578086334 |
| 28 | 1691859102 |