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 | -3 |
| 3 | -1 |
| 4 | 29 |
| 5 | -44 |
| 6 | -265 |
| 7 | 1114 |
| 8 | 1369 |
| 9 | -19076 |
| 10 | 20388 |
| 11 | 250977 |
| 12 | -875281 |
| 13 | -2116594 |
| 14 | 19136754 |
| 15 | -7765108 |
| 16 | -306092007 |
| 17 | 830209808 |
| 18 | 3388957208 |
| 19 | -22266676364 |
| 20 | -8185922076 |
| 21 | 413223401045 |
| 22 | -814031607979 |
| 23 | -5513566634947 |
| 24 | 27558060911119 |
| 25 | 35395095404776 |