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 | 1 |
| 2 | 7 |
| 3 | 15 |
| 4 | 97 |
| 5 | 209 |
| 6 | 1351 |
| 7 | 2911 |
| 8 | 18817 |
| 9 | 40545 |
| 10 | 262087 |
| 11 | 564719 |
| 12 | 3650401 |
| 13 | 7865521 |
| 14 | 50843527 |
| 15 | 109552575 |
| 16 | 708158977 |
| 17 | 1525870529 |
| 18 | 9863382151 |
| 19 | 21252634831 |
| 20 | 137379191137 |
| 21 | 296011017105 |
| 22 | 1913445293767 |
| 23 | 4122901604639 |
| 24 | 26650854921601 |
| 25 | 57424611447841 |
| 26 | 371198523608647 |