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 | 4 |
| 2 | 34 |
| 3 | 454 |
| 4 | 7384 |
| 5 | 133510 |
| 6 | 2583958 |
| 7 | 52468078 |
| 8 | 1104191608 |
| 9 | 23891534758 |
| 10 | 528527606698 |
| 11 | 11905777228618 |
| 12 | 272269758961018 |
| 13 | 6306419621308618 |
| 14 | 147677930682023818 |
| 15 | 3491114167267938298 |
| 16 | 83217317955857060788 |
| 17 | 1998209467779811473538 |
| 18 | 48293984598611551487038 |
| 19 | 1174012306200941229710038 |
| 20 | 28689784424223599507417938 |