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 | 4 |
| 3 | 7 |
| 4 | 22 |
| 5 | 64 |
| 6 | 191 |
| 7 | 567 |
| 8 | 1689 |
| 9 | 5033 |
| 10 | 15013 |
| 11 | 44809 |
| 12 | 133816 |
| 13 | 399802 |
| 14 | 1194949 |
| 15 | 3572693 |
| 16 | 10684758 |
| 17 | 31962456 |
| 18 | 95633229 |
| 19 | 286193409 |
| 20 | 856610214 |
| 21 | 2564317356 |
| 22 | 7677475521 |
| 23 | 22988860305 |
| 24 | 68843627049 |
| 25 | 206183053485 |
| 26 | 617563017927 |
| 27 | 1849887488987 |