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) |
|---|---|
| 0 | 3 |
| 1 | 24 |
| 2 | 162 |
| 3 | 1083 |
| 4 | 7260 |
| 5 | 48681 |
| 6 | 326406 |
| 7 | 2188536 |
| 8 | 14674041 |
| 9 | 98388840 |
| 10 | 659693103 |
| 11 | 4423214952 |
| 12 | 29657473194 |
| 13 | 198852130383 |
| 14 | 1333295304660 |
| 15 | 8939689838877 |
| 16 | 59940250397646 |
| 17 | 401896898269128 |
| 18 | 2694702070258437 |
| 19 | 18067865859946320 |
| 20 | 121144292846335179 |
| 21 | 812267469938047224 |