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 | 6 |
| 4 | 18 |
| 5 | 56 |
| 6 | 182 |
| 7 | 607 |
| 8 | 2064 |
| 9 | 7132 |
| 10 | 24970 |
| 11 | 88383 |
| 12 | 315748 |
| 13 | 1137014 |
| 14 | 4122762 |
| 15 | 15039631 |
| 16 | 55157790 |
| 17 | 203255438 |
| 18 | 752190764 |
| 19 | 2794352648 |
| 20 | 10417047964 |
| 21 | 38956725596 |
| 22 | 146108755556 |
| 23 | 549442692378 |
| 24 | 2071236137154 |
| 25 | 7825588757910 |