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 | 13 |
| 2 | 169 |
| 3 | 665 |
| 4 | 4181 |
| 5 | 21145 |
| 6 | 117835 |
| 7 | 628945 |
| 8 | 3426491 |
| 9 | 18496249 |
| 10 | 100245749 |
| 11 | 542220837 |
| 12 | 2935363929 |
| 13 | 15884981697 |
| 14 | 85980809657 |
| 15 | 465353448013 |
| 16 | 2518713741947 |
| 17 | 13632152020691 |
| 18 | 73782337553115 |
| 19 | 399336601092133 |
| 20 | 2161360508723247 |