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 | 2 |
| 2 | -5 |
| 3 | -1 |
| 4 | -11 |
| 5 | -13 |
| 6 | -35 |
| 7 | -61 |
| 8 | -131 |
| 9 | -253 |
| 10 | -515 |
| 11 | -1021 |
| 12 | -2051 |
| 13 | -4093 |
| 14 | -8195 |
| 15 | -16381 |
| 16 | -32771 |
| 17 | -65533 |
| 18 | -131075 |
| 19 | -262141 |
| 20 | -524291 |
| 21 | -1048573 |
| 22 | -2097155 |
| 23 | -4194301 |
| 24 | -8388611 |
| 25 | -16777213 |
| 26 | -33554435 |
| 27 | -67108861 |
| 28 | -134217731 |
| 29 | -268435453 |
| 30 | -536870915 |
| 31 | -1073741821 |
| 32 | -2147483651 |