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 | 5 |
| 3 | 9 |
| 4 | 20 |
| 5 | 39 |
| 6 | 80 |
| 7 | 159 |
| 8 | 320 |
| 9 | 639 |
| 10 | 1280 |
| 11 | 2559 |
| 12 | 5120 |
| 13 | 10239 |
| 14 | 20480 |
| 15 | 40959 |
| 16 | 81920 |
| 17 | 163839 |
| 18 | 327680 |
| 19 | 655359 |
| 20 | 1310720 |
| 21 | 2621439 |
| 22 | 5242880 |
| 23 | 10485759 |
| 24 | 20971520 |
| 25 | 41943039 |
| 26 | 83886080 |
| 27 | 167772159 |
| 28 | 335544320 |
| 29 | 671088639 |
| 30 | 1342177280 |
| 31 | 2684354559 |
| 32 | 5368709120 |
| 33 | 10737418239 |