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 | 10 |
| 2 | 80 |
| 3 | 580 |
| 4 | 4660 |
| 5 | 37960 |
| 6 | 311378 |
| 7 | 2559658 |
| 8 | 21057948 |
| 9 | 173287588 |
| 10 | 1426133270 |
| 11 | 11737272106 |
| 12 | 96600478510 |
| 13 | 795047628502 |
| 14 | 6543462720560 |
| 15 | 53854541701240 |
| 16 | 443238127915788 |
| 17 | 3647975524214452 |
| 18 | 30023874009147704 |
| 19 | 247105006940966092 |