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 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 31 |
| 5 | 117 |
| 6 | 479 |
| 7 | 2061 |
| 8 | 9183 |
| 9 | 42021 |
| 10 | 196239 |
| 11 | 931457 |
| 12 | 4480531 |
| 13 | 21793257 |
| 14 | 107004891 |
| 15 | 529656765 |
| 16 | 2640160039 |
| 17 | 13241371629 |
| 18 | 66771501151 |
| 19 | 338333343825 |
| 20 | 1721768732423 |
| 21 | 8796192611917 |
| 22 | 45096680384635 |
| 23 | 231945566136129 |
| 24 | 1196461977291959 |
| 25 | 6188390166782849 |