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 | 4 |
| 4 | 8 |
| 5 | -16 |
| 6 | -32 |
| 7 | -64 |
| 8 | 128 |
| 9 | -256 |
| 10 | -1536 |
| 11 | -3072 |
| 12 | 2048 |
| 13 | 4096 |
| 14 | 8192 |
| 15 | -16384 |
| 16 | 32768 |
| 17 | -65536 |
| 18 | -393216 |
| 19 | -2359296 |
| 20 | 14155776 |
| 21 | 28311552 |
| 22 | -94371840 |
| 23 | 62914560 |
| 24 | 8388608 |
| 25 | 16777216 |
| 26 | -570425344 |
| 27 | -1140850688 |
| 28 | -134217728 |
| 29 | 268435456 |
| 30 | -8053063680 |
| 31 | 16106127360 |
| 32 | 2147483648 |
| 33 | -4294967296 |
| 34 | 111669149696 |
| 35 | 670014898176 |
| 36 | 927712935936 |
| 37 | 5566277615616 |