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 | 3 |
| 2 | 10 |
| 3 | 35 |
| 4 | 132 |
| 5 | 517 |
| 6 | 2054 |
| 7 | 8199 |
| 8 | 32776 |
| 9 | 131081 |
| 10 | 524298 |
| 11 | 2097163 |
| 12 | 8388620 |
| 13 | 33554445 |
| 14 | 134217742 |
| 15 | 536870927 |
| 16 | 2147483664 |
| 17 | 8589934609 |
| 18 | 34359738386 |
| 19 | 137438953491 |
| 20 | 549755813908 |
| 21 | 2199023255573 |
| 22 | 8796093022230 |
| 23 | 35184372088855 |
| 24 | 140737488355352 |
| 25 | 562949953421337 |