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 | 0 |
| 2 | 11 |
| 3 | 77 |
| 4 | 431 |
| 5 | 2913 |
| 6 | 19393 |
| 7 | 128921 |
| 8 | 857789 |
| 9 | 5706297 |
| 10 | 37961366 |
| 11 | 252538085 |
| 12 | 1680012401 |
| 13 | 11176296913 |
| 14 | 74350419884 |
| 15 | 494616846377 |
| 16 | 3290443118074 |
| 17 | 21889703025083 |
| 18 | 145621450295042 |
| 19 | 968748034460686 |
| 20 | 6444605189965405 |