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 | 28 |
| 2 | 128 |
| 3 | 544 |
| 4 | 2384 |
| 5 | 10384 |
| 6 | 45392 |
| 7 | 198352 |
| 8 | 867152 |
| 9 | 3791056 |
| 10 | 16575056 |
| 11 | 72469456 |
| 12 | 316854608 |
| 13 | 1385372368 |
| 14 | 6057228368 |
| 15 | 26483886544 |
| 16 | 115794964304 |
| 17 | 506288081104 |
| 18 | 2213633766992 |
| 19 | 9678629263312 |
| 20 | 42317689343312 |
| 21 | 185024841512656 |