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 | 19 |
| 2 | 151 |
| 3 | 979 |
| 4 | 7391 |
| 5 | 56769 |
| 6 | 446635 |
| 7 | 3562417 |
| 8 | 28719839 |
| 9 | 233396143 |
| 10 | 1908631671 |
| 11 | 15685438183 |
| 12 | 129415466639 |
| 13 | 1071158916743 |
| 14 | 8888586709041 |
| 15 | 73910874048609 |
| 16 | 615613183193519 |
| 17 | 5134422106241421 |
| 18 | 42869268105031999 |
| 19 | 358244686255795945 |