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) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 13 |
| 3 | 63 |
| 4 | 321 |
| 5 | 1683 |
| 6 | 8989 |
| 7 | 48639 |
| 8 | 265729 |
| 9 | 1462563 |
| 10 | 8097453 |
| 11 | 45046719 |
| 12 | 251595969 |
| 13 | 1409933619 |
| 14 | 7923848253 |
| 15 | 44642381823 |
| 16 | 252055236609 |
| 17 | 1425834724419 |
| 18 | 8079317057869 |
| 19 | 45849429914943 |
| 20 | 260543813797441 |
| 21 | 1482376214227923 |
| 22 | 8443414161166173 |
| 23 | 48141245001931263 |