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 | 0 |
| 1 | 5 |
| 2 | 55 |
| 3 | 610 |
| 4 | 6765 |
| 5 | 75025 |
| 6 | 832040 |
| 7 | 9227465 |
| 8 | 102334155 |
| 9 | 1134903170 |
| 10 | 12586269025 |
| 11 | 139583862445 |
| 12 | 1548008755920 |
| 13 | 17167680177565 |
| 14 | 190392490709135 |
| 15 | 2111485077978050 |
| 16 | 23416728348467685 |
| 17 | 259695496911122585 |
| 18 | 2880067194370816120 |
| 19 | 31940434634990099905 |