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 | 9 |
| 2 | 17 |
| 3 | 65 |
| 4 | 257 |
| 5 | 4097 |
| 6 | 16385 |
| 7 | 262145 |
| 8 | 1048577 |
| 9 | 16777217 |
| 10 | 1073741825 |
| 11 | 4294967297 |
| 12 | 274877906945 |
| 13 | 4398046511105 |
| 14 | 17592186044417 |
| 15 | 281474976710657 |
| 16 | 18014398509481985 |
| 17 | 1152921504606846977 |
| 18 | 4611686018427387905 |
| 19 | 295147905179352825857 |
| 20 | 4722366482869645213697 |