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 | 24 |
| 2 | 114 |
| 3 | 550 |
| 4 | 2668 |
| 5 | 12986 |
| 6 | 63348 |
| 7 | 309524 |
| 8 | 1514230 |
| 9 | 7415030 |
| 10 | 36339360 |
| 11 | 178207260 |
| 12 | 874402930 |
| 13 | 4292397700 |
| 14 | 21079558088 |
| 15 | 103555346934 |
| 16 | 508877542076 |
| 17 | 2501307731338 |
| 18 | 12297585994658 |
| 19 | 60472695897300 |
| 20 | 297423291148782 |