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 | 2 |
| 3 | 5 |
| 4 | 15 |
| 5 | 52 |
| 6 | 203 |
| 7 | 877 |
| 8 | 4139 |
| 9 | 21138 |
| 10 | 115885 |
| 11 | 677745 |
| 12 | 4206172 |
| 13 | 27577513 |
| 14 | 190289713 |
| 15 | 1377315050 |
| 16 | 10426866782 |
| 17 | 82350895629 |
| 18 | 677003941219 |
| 19 | 5781485704892 |
| 20 | 51193839084907 |
| 21 | 469251258854001 |
| 22 | 4445769329586348 |
| 23 | 43475305461354931 |
| 24 | 438270620701587657 |
| 25 | 4549243731200717053 |