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 | 7 |
| 2 | 19 |
| 3 | 62 |
| 4 | 253 |
| 5 | 1104 |
| 6 | 5082 |
| 7 | 24119 |
| 8 | 117016 |
| 9 | 577219 |
| 10 | 2881559 |
| 11 | 14517349 |
| 12 | 73646606 |
| 13 | 375647872 |
| 14 | 1924303223 |
| 15 | 9890611989 |
| 16 | 50972464766 |
| 17 | 263251147564 |
| 18 | 1361885016990 |
| 19 | 7055002534314 |
| 20 | 36586652345539 |
| 21 | 189899006940570 |