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 | 10 |
| 2 | 100 |
| 3 | 270 |
| 4 | 1450 |
| 5 | 5200 |
| 6 | 23530 |
| 7 | 92610 |
| 8 | 396100 |
| 9 | 1610950 |
| 10 | 6754210 |
| 11 | 27799200 |
| 12 | 115710130 |
| 13 | 478341370 |
| 14 | 1985702500 |
| 15 | 8222193630 |
| 16 | 34098329530 |
| 17 | 141276194800 |
| 18 | 585672013210 |
| 19 | 2427100765650 |
| 20 | 10060368444100 |
| 21 | 41694947333590 |