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 | 1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 37 |
| 4 | 351 |
| 5 | 3765 |
| 6 | 43752 |
| 7 | 536375 |
| 8 | 6842599 |
| 9 | 89984614 |
| 10 | 1212199424 |
| 11 | 16651935901 |
| 12 | 232477235048 |
| 13 | 3290090540717 |
| 14 | 47106320777132 |
| 15 | 681247106742555 |
| 16 | 9938641464083052 |
| 17 | 146113228303254020 |
| 18 | 2162784490438698636 |
| 19 | 32209221982817148364 |
| 20 | 482304350308369699381 |