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 | 5 |
| 2 | 22 |
| 3 | 86 |
| 4 | 304 |
| 5 | 992 |
| 6 | 3040 |
| 7 | 8864 |
| 8 | 24832 |
| 9 | 67328 |
| 10 | 177664 |
| 11 | 458240 |
| 12 | 1159168 |
| 13 | 2883584 |
| 14 | 7069696 |
| 15 | 17113088 |
| 16 | 40960000 |
| 17 | 97058816 |
| 18 | 227934208 |
| 19 | 530972672 |
| 20 | 1227882496 |
| 21 | 2820669440 |
| 22 | 6440353792 |
| 23 | 14623440896 |
| 24 | 33034338304 |
| 25 | 74272735232 |
| 26 | 166262210560 |
| 27 | 370675810304 |
| 28 | 823291543552 |
| 29 | 1822139875328 |