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 | 5 |
| 2 | 15 |
| 3 | 50 |
| 4 | 175 |
| 5 | 630 |
| 6 | 2310 |
| 7 | 8580 |
| 8 | 32175 |
| 9 | 121550 |
| 10 | 461890 |
| 11 | 1763580 |
| 12 | 6760390 |
| 13 | 26001500 |
| 14 | 100291500 |
| 15 | 387793800 |
| 16 | 1502700975 |
| 17 | 5834015550 |
| 18 | 22687838250 |
| 19 | 88363159500 |
| 20 | 344616322050 |
| 21 | 1345644686100 |
| 22 | 5260247409300 |
| 23 | 20583576819000 |
| 24 | 80619009207750 |
| 25 | 316026516094380 |
| 26 | 1239796332370260 |