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 | 1 |
| 2 | 4 |
| 3 | 9 |
| 4 | 19 |
| 5 | 45 |
| 6 | 127 |
| 7 | 491 |
| 8 | 2597 |
| 9 | 18905 |
| 10 | 180253 |
| 11 | 2176101 |
| 12 | 32236029 |
| 13 | 571516361 |
| 14 | 11885151437 |
| 15 | 285237145381 |
| 16 | 7794999370341 |
| 17 | 239867327549943 |
| 18 | 8232788441242931 |
| 19 | 312611538663794793 |
| 20 | 13040004273788572983 |