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 | 2 |
| 2 | 12 |
| 3 | 38 |
| 4 | 212 |
| 5 | 2538 |
| 6 | 6888 |
| 7 | 66592 |
| 8 | 210771 |
| 9 | 2059962 |
| 10 | 6696592 |
| 11 | 21081538 |
| 12 | 209868112 |
| 13 | 664488107 |
| 14 | 3800598038 |
| 15 | 18613286762 |
| 16 | 209820981888 |
| 17 | 666669703412 |
| 18 | 666516649788 |
| 19 | 6666894662768 |
| 20 | 49400874945738 |
| 21 | 156347319914172 |
| 22 | 210747466045038 |
| 23 | 5868938950479212 |
| 24 | 21081850261503238 |
| 25 | 66666663966850212 |