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 | 2 |
| 2 | 10 |
| 3 | 34 |
| 4 | 122 |
| 5 | 378 |
| 6 | 1242 |
| 7 | 3690 |
| 8 | 11266 |
| 9 | 32666 |
| 10 | 94994 |
| 11 | 267202 |
| 12 | 754546 |
| 13 | 2072578 |
| 14 | 5691514 |
| 15 | 15364290 |
| 16 | 41321962 |
| 17 | 109634586 |
| 18 | 290048746 |
| 19 | 758630698 |
| 20 | 1977954706 |
| 21 | 5111900410 |
| 22 | 13161995010 |
| 23 | 33645284962 |
| 24 | 85727394018 |
| 25 | 217042978882 |
| 26 | 547750831210 |
| 27 | 1375147078146 |
| 28 | 3441516792442 |