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 | 4 |
| 2 | 14 |
| 3 | 106 |
| 4 | 2142 |
| 5 | 124150 |
| 6 | 21231450 |
| 7 | 10794801654 |
| 8 | 16397345136778 |
| 9 | 74754715306888786 |
| 10 | 1026191624073867290710 |
| 11 | 42506394853041064742716162 |
| 12 | 5320474615969510569494723118086 |
| 13 | 2014671515857822813610223858063766522 |