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 | 2 |
| 3 | 2 |
| 4 | 4 |
| 5 | 2 |
| 6 | 7 |
| 7 | -5 |
| 8 | 16 |
| 9 | -40 |
| 10 | 74 |
| 11 | -196 |
| 12 | 431 |
| 13 | -999 |
| 14 | 2433 |
| 15 | -5575 |
| 16 | 13600 |
| 17 | -32264 |
| 18 | 77794 |
| 19 | -188630 |
| 20 | 456078 |
| 21 | -1113702 |
| 22 | 2716432 |
| 23 | -6656382 |
| 24 | 16351231 |
| 25 | -40236773 |
| 26 | 99308252 |
| 27 | -245471638 |
| 28 | 608083547 |
| 29 | -1508944093 |
| 30 | 3750434282 |
| 31 | -9336906118 |
| 32 | 23277132752 |
| 33 | -58112501728 |
| 34 | 145266946742 |
| 35 | -363574425058 |