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 | 1 |
| 2 | 3 |
| 3 | 11 |
| 4 | 43 |
| 5 | 170 |
| 6 | 657 |
| 7 | 2392 |
| 8 | 7675 |
| 9 | 17603 |
| 10 | -11898 |
| 11 | -529678 |
| 12 | -4783303 |
| 13 | -33099464 |
| 14 | -201744488 |
| 15 | -1130700432 |
| 16 | -5917753701 |
| 17 | -28985131575 |
| 18 | -131668554663 |
| 19 | -540199800203 |
| 20 | -1862208441834 |
| 21 | -4014999475540 |
| 22 | 10784817197302 |
| 23 | 222255824910088 |
| 24 | 1973412557775753 |