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 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 15 |
| 6 | 97 |
| 7 | 528 |
| 8 | 7525 |
| 9 | 81413 |
| 10 | 2330257 |
| 11 | 53229494 |
| 12 | 2883887781 |
| 13 | 143434131379 |
| 14 | 14268520503521 |
| 15 | 1569684574492244 |
| 16 | 282300076226827269 |
| 17 | 69232924049740233209 |
| 18 | 22337274702237239579729 |
| 19 | 12261557957001826246975754 |
| 20 | 7069170473480519272781373829 |