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 | 3 |
| 2 | 31 |
| 3 | 265 |
| 4 | 2326 |
| 5 | 20753 |
| 6 | 186657 |
| 7 | 1694289 |
| 8 | 15522934 |
| 9 | 143361278 |
| 10 | 1332987907 |
| 11 | 12466213899 |
| 12 | 117166026836 |
| 13 | 1105962031475 |
| 14 | 10478814259427 |
| 15 | 99613914990801 |
| 16 | 949727475528388 |
| 17 | 9078425620890083 |
| 18 | 86983554771459735 |
| 19 | 835176988544997091 |
| 20 | 8034305823411044844 |
| 21 | 77423350444120266442 |