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 | 10 |
| 2 | 115 |
| 3 | 1450 |
| 4 | 19425 |
| 5 | 271502 |
| 6 | 3915100 |
| 7 | 57821940 |
| 8 | 870238200 |
| 9 | 13298907050 |
| 10 | 205811513765 |
| 11 | 3218995093860 |
| 12 | 50802419972395 |
| 13 | 808016193159000 |
| 14 | 12938696992921000 |
| 15 | 208419656266988904 |
| 16 | 3374960506795660365 |
| 17 | 54907659530154222000 |
| 18 | 897060906625956765000 |