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 | 0 |
| 1 | 6 |
| 2 | 42 |
| 3 | 258 |
| 4 | 1554 |
| 5 | 9330 |
| 6 | 55986 |
| 7 | 335922 |
| 8 | 2015538 |
| 9 | 12093234 |
| 10 | 72559410 |
| 11 | 435356466 |
| 12 | 2612138802 |
| 13 | 15672832818 |
| 14 | 94036996914 |
| 15 | 564221981490 |
| 16 | 3385331888946 |
| 17 | 20311991333682 |
| 18 | 121871948002098 |
| 19 | 731231688012594 |
| 20 | 4387390128075570 |
| 21 | 26324340768453426 |
| 22 | 157946044610720562 |