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 | 4 |
| 1 | 4 |
| 2 | 10 |
| 3 | 33 |
| 4 | 106 |
| 5 | 309 |
| 6 | 965 |
| 7 | 3022 |
| 8 | 9489 |
| 9 | 29813 |
| 10 | 93649 |
| 11 | 294209 |
| 12 | 924271 |
| 13 | 2903678 |
| 14 | 9122173 |
| 15 | 28658147 |
| 16 | 90032221 |
| 17 | 282844574 |
| 18 | 888582413 |
| 19 | 2791563955 |
| 20 | 8769956797 |
| 21 | 27551631845 |
| 22 | 86556004193 |
| 23 | 271923706897 |
| 24 | 854273519921 |
| 25 | 2683779414319 |