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 | 4 |
| 2 | 10 |
| 3 | 29 |
| 4 | 97 |
| 5 | 366 |
| 6 | 1534 |
| 7 | 7050 |
| 8 | 35167 |
| 9 | 188834 |
| 10 | 1084123 |
| 11 | 6616633 |
| 12 | 42711918 |
| 13 | 290232665 |
| 14 | 2066233824 |
| 15 | 15337289086 |
| 16 | 118111928594 |
| 17 | 938944428249 |
| 18 | 7667833845713 |
| 19 | 64035036092080 |
| 20 | 544629289107076 |
| 21 | 4700922875545352 |