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 | 1 |
| 2 | 3 |
| 3 | 4 |
| 4 | 15 |
| 5 | 38 |
| 6 | 136 |
| 7 | 458 |
| 8 | 1781 |
| 9 | 6912 |
| 10 | 28141 |
| 11 | 115761 |
| 12 | 485607 |
| 13 | 2056341 |
| 14 | 8800541 |
| 15 | 37945282 |
| 16 | 164766522 |
| 17 | 719617100 |
| 18 | 3159529303 |
| 19 | 13936202144 |