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 | 4 |
| 2 | 5 |
| 3 | 10 |
| 4 | 20 |
| 5 | 40 |
| 6 | 80 |
| 7 | 491531 |
| 8 | 983062 |
| 9 | 1966124 |
| 10 | 2457655 |
| 11 | 3932248 |
| 12 | 4915310 |
| 13 | 6389903 |
| 14 | 9339089 |
| 15 | 9830620 |
| 16 | 12288275 |
| 17 | 12779806 |
| 18 | 18678178 |
| 19 | 19169709 |
| 20 | 19661240 |
| 21 | 24576550 |
| 22 | 25559612 |
| 23 | 28017267 |
| 24 | 31949515 |
| 25 | 37356356 |
| 26 | 38339418 |
| 27 | 39322480 |
| 28 | 46695445 |
| 29 | 49153100 |
| 30 | 51119224 |
| 31 | 56034534 |