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 | 6 |
| 3 | 24 |
| 4 | 130 |
| 5 | 688 |
| 6 | 4211 |
| 7 | 26840 |
| 8 | 184153 |
| 9 | 1328155 |
| 10 | 10078617 |
| 11 | 79926478 |
| 12 | 660616432 |
| 13 | 5671793248 |
| 14 | 50459837996 |
| 15 | 464139053799 |
| 16 | 4405521306315 |
| 17 | 43077862741114 |
| 18 | 433275511964227 |
| 19 | 4476516495577776 |
| 20 | 47451864583578111 |
| 21 | 515494036824348917 |
| 22 | 5733423512317010811 |
| 23 | 65226494052113260251 |
| 24 | 758377712833720838677 |
| 25 | 9004484581478188581057 |