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 | 13 |
| 2 | 145 |
| 3 | 1597 |
| 4 | 17569 |
| 5 | 193261 |
| 6 | 2125873 |
| 7 | 23384605 |
| 8 | 257230657 |
| 9 | 2829537229 |
| 10 | 31124909521 |
| 11 | 342374004733 |
| 12 | 3766114052065 |
| 13 | 41427254572717 |
| 14 | 455699800299889 |
| 15 | 5012697803298781 |
| 16 | 55139675836286593 |
| 17 | 606536434199152525 |
| 18 | 6671900776190677777 |
| 19 | 73390908538097455549 |
| 20 | 807299993919072011041 |