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 | 3 |
| 2 | 6 |
| 3 | 18 |
| 4 | 75 |
| 5 | 342 |
| 6 | 1773 |
| 7 | 9894 |
| 8 | 58596 |
| 9 | 362061 |
| 10 | 2314119 |
| 11 | 15185223 |
| 12 | 101830986 |
| 13 | 695253993 |
| 14 | 4819762446 |
| 15 | 33851833506 |
| 16 | 240472935735 |
| 17 | 1725315714729 |
| 18 | 12487872432924 |
| 19 | 91097741283408 |
| 20 | 669227023979088 |
| 21 | 4947500029023540 |
| 22 | 36786363204267282 |
| 23 | 274949933519917908 |