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 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 7 |
| 6 | 7 |
| 7 | -47 |
| 8 | -549 |
| 9 | -4284 |
| 10 | -30756 |
| 11 | -218315 |
| 12 | -1571731 |
| 13 | -11603343 |
| 14 | -88284675 |
| 15 | -693810426 |
| 16 | -5636074516 |
| 17 | -47324368509 |
| 18 | -410556832893 |
| 19 | -3677474325071 |
| 20 | -33983530496537 |
| 21 | -323712524813480 |
| 22 | -3175734966375132 |
| 23 | -32058728131612719 |
| 24 | -332733970940411623 |
| 25 | -3547642104951509087 |