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) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 18 |
| 5 | 110 |
| 6 | 772 |
| 7 | 5936 |
| 8 | 48618 |
| 9 | 417398 |
| 10 | 3716972 |
| 11 | 34086194 |
| 12 | 320225348 |
| 13 | 3069943298 |
| 14 | 29943487732 |
| 15 | 296447910268 |
| 16 | 2973356043818 |
| 17 | 30166687749922 |
| 18 | 309197338572932 |
| 19 | 3198206243665998 |
| 20 | 33353864893990660 |
| 21 | 350443763627186256 |
| 22 | 3707087785160487888 |
| 23 | 39458245623693926384 |
| 24 | 422389058260155207568 |