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 | 3 |
| 2 | 9 |
| 3 | 25 |
| 4 | 67 |
| 5 | 176 |
| 6 | 456 |
| 7 | 1169 |
| 8 | 2971 |
| 9 | 7496 |
| 10 | 18796 |
| 11 | 46880 |
| 12 | 116386 |
| 13 | 287775 |
| 14 | 709005 |
| 15 | 1741247 |
| 16 | 4264131 |
| 17 | 10415559 |
| 18 | 25381773 |
| 19 | 61721980 |
| 20 | 149801330 |
| 21 | 362926749 |
| 22 | 877831299 |
| 23 | 2120050410 |
| 24 | 5112962906 |
| 25 | 12314976142 |
| 26 | 29625637490 |
| 27 | 71188510125 |