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 | 2 |
| 2 | 4 |
| 3 | 8 |
| 4 | 16 |
| 5 | 32 |
| 6 | 65 |
| 7 | 136 |
| 8 | 298 |
| 9 | 691 |
| 10 | 1694 |
| 11 | 4340 |
| 12 | 11433 |
| 13 | 30510 |
| 14 | 81592 |
| 15 | 217238 |
| 16 | 573970 |
| 17 | 1503296 |
| 18 | 3904181 |
| 19 | 10065079 |
| 20 | 25796324 |
| 21 | 65837541 |
| 22 | 167602092 |
| 23 | 426213784 |
| 24 | 1084095329 |
| 25 | 2760717190 |
| 26 | 7043305930 |
| 27 | 18008810836 |
| 28 | 46151503544 |
| 29 | 118529776510 |
| 30 | 304998080821 |