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) |
|---|---|
| 1 | 1 |
| 2 | -2 |
| 3 | 3 |
| 4 | -5 |
| 5 | 7 |
| 6 | -14 |
| 7 | 11 |
| 8 | -66 |
| 9 | -127 |
| 10 | -992 |
| 11 | -5029 |
| 12 | -30899 |
| 13 | -193321 |
| 14 | -1285300 |
| 15 | -8942561 |
| 16 | -65113125 |
| 17 | -494605857 |
| 18 | -3911658640 |
| 19 | -32145949441 |
| 20 | -274036507173 |
| 21 | -2419502677445 |
| 22 | -22093077575496 |
| 23 | -208364964369913 |
| 24 | -2027216779571754 |
| 25 | -20323053380033763 |
| 26 | -209715614081160850 |