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 | 9 |
| 2 | 33 |
| 3 | 97 |
| 4 | 257 |
| 5 | 641 |
| 6 | 1537 |
| 7 | 3585 |
| 8 | 8193 |
| 9 | 18433 |
| 10 | 40961 |
| 11 | 90113 |
| 12 | 196609 |
| 13 | 425985 |
| 14 | 917505 |
| 15 | 1966081 |
| 16 | 4194305 |
| 17 | 8912897 |
| 18 | 18874369 |
| 19 | 39845889 |
| 20 | 83886081 |
| 21 | 176160769 |
| 22 | 369098753 |
| 23 | 771751937 |
| 24 | 1610612737 |
| 25 | 3355443201 |
| 26 | 6979321857 |
| 27 | 14495514625 |
| 28 | 30064771073 |
| 29 | 62277025793 |