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 | 6 |
| 2 | 36 |
| 3 | 114 |
| 4 | 450 |
| 5 | 1644 |
| 6 | 6186 |
| 7 | 23010 |
| 8 | 85992 |
| 9 | 320742 |
| 10 | 1197318 |
| 11 | 4467984 |
| 12 | 16675494 |
| 13 | 62232582 |
| 14 | 232257108 |
| 15 | 866792178 |
| 16 | 3234917538 |
| 17 | 12072868380 |
| 18 | 45056571498 |
| 19 | 168153392514 |
| 20 | 627557039160 |
| 21 | 2342074698438 |
| 22 | 8740741860870 |
| 23 | 32620892573088 |