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) |
|---|---|
| 2 | 5 |
| 3 | 13 |
| 4 | 29 |
| 5 | 61 |
| 6 | 113 |
| 7 | 251 |
| 8 | 509 |
| 9 | 1021 |
| 10 | 2039 |
| 11 | 4093 |
| 12 | 8179 |
| 13 | 16381 |
| 14 | 32749 |
| 15 | 65521 |
| 16 | 131063 |
| 17 | 262139 |
| 18 | 524269 |
| 19 | 1048573 |
| 20 | 2097143 |
| 21 | 4194301 |
| 22 | 8388593 |
| 23 | 16777213 |
| 24 | 33554393 |
| 25 | 67108859 |
| 26 | 134217689 |
| 27 | 268435399 |
| 28 | 536870909 |
| 29 | 1073741789 |
| 30 | 2147483629 |