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 | 4 |
| 1 | 8 |
| 2 | 52 |
| 3 | 304 |
| 4 | 1052 |
| 5 | 10312 |
| 6 | 147916 |
| 7 | 135904 |
| 8 | 2490548 |
| 9 | 44257352 |
| 10 | 47028692 |
| 11 | 1023461776 |
| 12 | 5385020324 |
| 13 | 15411418072 |
| 14 | 467009482388 |
| 15 | 13895021563328 |
| 16 | 14442004718228 |
| 17 | 13926277743608 |
| 18 | 533322720625196 |
| 19 | 516197940314096 |
| 20 | 21831981985010836 |
| 21 | 911392701638017048 |
| 22 | 937558224301357108 |