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) |
|---|---|
| 1 | 81 |
| 2 | 1944 |
| 3 | 11361 |
| 4 | 45453 |
| 5 | 164514 |
| 6 | 562760 |
| 7 | 1825800 |
| 8 | 5585818 |
| 9 | 16074063 |
| 10 | 43567313 |
| 11 | 111632420 |
| 12 | 271667665 |
| 13 | 630966702 |
| 14 | 1405080075 |
| 15 | 3012670262 |
| 16 | 6242914246 |
| 17 | 12544093805 |
| 18 | 24510622826 |
| 19 | 46689053477 |
| 20 | 86888070112 |
| 21 | 158272032306 |