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) |
|---|---|
| 3 | 1 |
| 4 | 11 |
| 5 | 267 |
| 6 | 2620 |
| 7 | 16305 |
| 8 | 77040 |
| 9 | 303553 |
| 10 | 1055231 |
| 11 | 3358268 |
| 12 | 10039132 |
| 13 | 28714818 |
| 14 | 79649852 |
| 15 | 216360858 |
| 16 | 579601543 |
| 17 | 1538746237 |
| 18 | 4061993928 |
| 19 | 10685640859 |
| 20 | 28051744332 |
| 21 | 73551897971 |
| 22 | 192720956939 |
| 23 | 504774508726 |
| 24 | 1321827638248 |
| 25 | 3461013838244 |
| 26 | 9061623069576 |
| 27 | 23724397134644 |