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 | 2 |
| 3 | 3 |
| 4 | 8 |
| 5 | 38 |
| 6 | 268 |
| 7 | 2578 |
| 8 | 31672 |
| 9 | 475120 |
| 10 | 8427696 |
| 11 | 172607454 |
| 12 | 4008441848 |
| 13 | 104061288740 |
| 14 | 2985810416824 |
| 15 | 93812980749076 |
| 16 | 3202899902480872 |
| 17 | 118054380417848192 |
| 18 | 4671653916923940952 |
| 19 | 197528462484409468792 |
| 20 | 8886812830338447522120 |
| 21 | 423862241146246310158108 |
| 22 | 21362480654281867734050272 |