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 | 0 |
| 1 | 1 |
| 2 | 11 |
| 3 | 64 |
| 4 | 282 |
| 5 | 1071 |
| 6 | 3729 |
| 7 | 12310 |
| 8 | 39296 |
| 9 | 122773 |
| 10 | 378279 |
| 11 | 1154988 |
| 12 | 3505542 |
| 13 | 10598107 |
| 14 | 31957661 |
| 15 | 96200098 |
| 16 | 289255020 |
| 17 | 869075073 |
| 18 | 2609845875 |
| 19 | 7834779640 |
| 20 | 23514823730 |
| 21 | 70565441671 |
| 22 | 211738266921 |
| 23 | 635298685614 |
| 24 | 1906063827672 |
| 25 | 5718527025901 |
| 26 | 17156252164799 |
| 27 | 51470098670020 |