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 | 3 |
| 4 | 7 |
| 5 | 14 |
| 6 | 33 |
| 7 | 81 |
| 8 | 215 |
| 9 | 601 |
| 10 | 1808 |
| 11 | 5721 |
| 12 | 19133 |
| 13 | 67218 |
| 14 | 247377 |
| 15 | 950679 |
| 16 | 3806360 |
| 17 | 15837196 |
| 18 | 68336348 |
| 19 | 305196782 |
| 20 | 1408294018 |
| 21 | 6703197359 |
| 22 | 32861879994 |
| 23 | 165699114887 |
| 24 | 858237346563 |
| 25 | 4560774579700 |
| 26 | 24839216194151 |
| 27 | 138505159164086 |
| 28 | 789982051646096 |
| 29 | 4604866422703625 |