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) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 5 |
| 5 | 8 |
| 6 | 13 |
| 7 | 16 |
| 8 | 29 |
| 9 | 61 |
| 10 | 64 |
| 11 | 125 |
| 12 | 128 |
| 13 | 509 |
| 14 | 1021 |
| 15 | 4093 |
| 16 | 4096 |
| 17 | 16381 |
| 18 | 32768 |
| 19 | 65536 |
| 20 | 262144 |
| 21 | 1048573 |
| 22 | 4194301 |
| 23 | 16777213 |
| 24 | 268435456 |
| 25 | 536870909 |
| 26 | 1073741824 |
| 27 | 36028797018963968 |