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 | 21 |
| 2 | 23 |
| 3 | 94 |
| 4 | 217 |
| 5 | 661 |
| 6 | 2013 |
| 7 | 6311 |
| 8 | 19497 |
| 9 | 60253 |
| 10 | 186797 |
| 11 | 578385 |
| 12 | 1790605 |
| 13 | 5545571 |
| 14 | 17172267 |
| 15 | 53173813 |
| 16 | 164661159 |
| 17 | 509890659 |
| 18 | 1578918645 |
| 19 | 4889288817 |
| 20 | 15140189411 |
| 21 | 46883090855 |
| 22 | 145178205375 |
| 23 | 449559001303 |
| 24 | 1392104734057 |
| 25 | 4310792424591 |