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 | 5 |
| 2 | 23 |
| 3 | 83 |
| 4 | 291 |
| 5 | 1015 |
| 6 | 3539 |
| 7 | 12339 |
| 8 | 43043 |
| 9 | 150239 |
| 10 | 524723 |
| 11 | 1833771 |
| 12 | 6412467 |
| 13 | 22437095 |
| 14 | 78553491 |
| 15 | 275180323 |
| 16 | 964534339 |
| 17 | 3382685743 |
| 18 | 11869824179 |
| 19 | 41673547291 |
| 20 | 146387820371 |
| 21 | 514484547639 |
| 22 | 1809077492883 |
| 23 | 6364347723667 |
| 24 | 22400458807139 |
| 25 | 78878848178815 |
| 26 | 277881197881011 |