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 | 2 |
| 2 | 3 |
| 3 | 3 |
| 4 | 3 |
| 5 | 4 |
| 6 | -6 |
| 7 | 49 |
| 8 | -178 |
| 9 | 76 |
| 10 | 8633 |
| 11 | -124131 |
| 12 | 1202662 |
| 13 | -8252662 |
| 14 | 16009623 |
| 15 | 730544913 |
| 16 | -17236420029 |
| 17 | 256679586178 |
| 18 | -2787185606474 |
| 19 | 15947981601793 |
| 20 | 215110909342463 |
| 21 | -9723413157539188 |
| 22 | 216257810122284716 |
| 23 | -3515999949642686709 |