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 | 2 |
| 1 | 2 |
| 2 | 3 |
| 3 | 13 |
| 4 | 89 |
| 5 | 659 |
| 6 | 5443 |
| 7 | 49033 |
| 8 | 484037 |
| 9 | 5222429 |
| 10 | 61194647 |
| 11 | 774825383 |
| 12 | 10552185239 |
| 13 | 153903050137 |
| 14 | 2394322471421 |
| 15 | 39588599419319 |
| 16 | 693389445083107 |
| 17 | 12826386978604427 |
| 18 | 249902442548157673 |
| 19 | 5115640857307591139 |
| 20 | 109776797549312197217 |
| 21 | 2464348772728229970857 |