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 | -4 |
| 2 | 8 |
| 3 | 8 |
| 4 | -40 |
| 5 | -184 |
| 6 | -232 |
| 7 | 1928 |
| 8 | 19160 |
| 9 | 116936 |
| 10 | 600728 |
| 11 | 2826248 |
| 12 | 12623960 |
| 13 | 54550856 |
| 14 | 230564888 |
| 15 | 959736968 |
| 16 | 3952166360 |
| 17 | 16149893576 |
| 18 | 65626404248 |
| 19 | 265592398088 |
| 20 | 1071642518360 |
| 21 | 4314414017096 |
| 22 | 17341238230808 |
| 23 | 69615800073608 |
| 24 | 279215943071960 |
| 25 | 1119122403273416 |