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 | 4 |
| 4 | 9 |
| 5 | 22 |
| 6 | 53 |
| 7 | 131 |
| 8 | 337 |
| 9 | 869 |
| 10 | 2213 |
| 11 | 5691 |
| 12 | 14517 |
| 13 | 37017 |
| 14 | 93731 |
| 15 | 237465 |
| 16 | 601093 |
| 17 | 1519815 |
| 18 | 3842575 |
| 19 | 9720769 |
| 20 | 24599577 |
| 21 | 62283535 |
| 22 | 157807915 |
| 23 | 400094029 |
| 24 | 1014905643 |
| 25 | 2576046289 |
| 26 | 6541989261 |
| 27 | 16621908599 |
| 28 | 42251728111 |
| 29 | 107445714789 |
| 30 | 273335703079 |