n | a(n) |
---|---|
0 | 1 |
1 | 7 |
2 | 28 |
3 | 140 |
4 | 658 |
5 | 3164 |
6 | 15106 |
7 | 72302 |
8 | 345775 |
9 | 1654092 |
10 | 7911970 |
11 | 37846314 |
12 | 181033035 |
13 | 865951710 |
14 | 4142180085 |
15 | 19813648817 |
16 | 94776329265 |
17 | 453351783116 |
18 | 2168556616440 |
19 | 10373043626906 |
20 | 49618272850056 |
21 | 237343357526002 |
[1,7,28,140,658,3164,15106,72302,345775,1654092, 7911970,37846314,181033035,865951710,4142180085, 19813648817,94776329265,453351783116, 2168556616440,10373043626906,49618272850056, 237343357526002] |