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 | 7 |
| 3 | 24 |
| 4 | 93 |
| 5 | 362 |
| 6 | 1452 |
| 7 | 5880 |
| 8 | 24089 |
| 9 | 99386 |
| 10 | 412637 |
| 11 | 1721500 |
| 12 | 7211536 |
| 13 | 30312960 |
| 14 | 127790379 |
| 15 | 540082784 |
| 16 | 2287577537 |
| 17 | 9707988994 |
| 18 | 41269156159 |
| 19 | 175705272784 |
| 20 | 749099069183 |
| 21 | 3197651758190 |
| 22 | 13665035075871 |
| 23 | 58456775063400 |
| 24 | 250302852165368 |
| 25 | 1072680809038112 |
| 26 | 4600656305265352 |
| 27 | 19746390910296372 |