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 | 4 |
| 2 | 9 |
| 3 | 21 |
| 4 | 51 |
| 5 | 127 |
| 6 | 324 |
| 7 | 844 |
| 8 | 2243 |
| 9 | 6073 |
| 10 | 16737 |
| 11 | 46905 |
| 12 | 133556 |
| 13 | 386062 |
| 14 | 1132107 |
| 15 | 3365627 |
| 16 | 10137558 |
| 17 | 30920924 |
| 18 | 95456942 |
| 19 | 298125982 |
| 20 | 941555265 |
| 21 | 3005897555 |
| 22 | 9696696210 |
| 23 | 31596681866 |
| 24 | 103963289341 |
| 25 | 345299662267 |
| 26 | 1157307776719 |