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 | 0 |
| 2 | 2 |
| 3 | 3 |
| 4 | -8 |
| 5 | 5 |
| 6 | 696 |
| 7 | 2527 |
| 8 | -40144 |
| 9 | -178407 |
| 10 | 8337880 |
| 11 | 76134971 |
| 12 | -1781542344 |
| 13 | -24938260763 |
| 14 | 691630553264 |
| 15 | 14216543752335 |
| 16 | -312910463346464 |
| 17 | -9343318015483471 |
| 18 | 195539694928047144 |
| 19 | 8145971436703039363 |
| 20 | -142317653823753257560 |
| 21 | -8498984155838272275459 |