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 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | -3 |
| 6 | -11 |
| 7 | -23 |
| 8 | -39 |
| 9 | -43 |
| 10 | -3 |
| 11 | 129 |
| 12 | 417 |
| 13 | 877 |
| 14 | 1349 |
| 15 | 1305 |
| 16 | -407 |
| 17 | -5627 |
| 18 | -16243 |
| 19 | -32079 |
| 20 | -46287 |
| 21 | -37987 |
| 22 | 35285 |
| 23 | 236873 |
| 24 | 623609 |
| 25 | 1162293 |
| 26 | 1559837 |
| 27 | 1009889 |
| 28 | -2034495 |
| 29 | -9728051 |
| 30 | -23660955 |
| 31 | -41633415 |
| 32 | -51467895 |
| 33 | -22390171 |
| 34 | 101331373 |
| 35 | 391586577 |
| 36 | 887713361 |
| 37 | 1473400829 |
| 38 | 1653762805 |
| 39 | 267778473 |
| 40 | -4669059303 |
| 41 | -15499500395 |