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 | 18 |
| 2 | 171 |
| 3 | 1158 |
| 4 | 6309 |
| 5 | 29430 |
| 6 | 121962 |
| 7 | 460008 |
| 8 | 1605996 |
| 9 | 5254334 |
| 10 | 16260867 |
| 11 | 47949804 |
| 12 | 135509922 |
| 13 | 368764290 |
| 14 | 970099191 |
| 15 | 2475106170 |
| 16 | 6141671649 |
| 17 | 14856839874 |
| 18 | 35107961175 |
| 19 | 81189855828 |
| 20 | 184033842021 |
| 21 | 409446105486 |
| 22 | 895231350108 |
| 23 | 1925717858910 |
| 24 | 4079428991751 |
| 25 | 8518121246538 |