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 | 3 |
| 2 | 41 |
| 3 | 147 |
| 4 | 8649 |
| 5 | 32307 |
| 6 | 487889 |
| 7 | 1856307 |
| 8 | 454689481 |
| 9 | 1748274987 |
| 10 | 26989009929 |
| 11 | 104482114467 |
| 12 | 6488426222001 |
| 13 | 25239009088827 |
| 14 | 393449178700161 |
| 15 | 1535897056631667 |
| 16 | 1537112996582116041 |
| 17 | 6016831929058214523 |
| 18 | 94316599529950360769 |
| 19 | 369994845516850143483 |
| 20 | 23244865440911268112681 |