n | a(n) |
---|---|
1 | 0 |
2 | 0 |
3 | 1 |
4 | 7 |
5 | 39 |
6 | 188 |
7 | 884 |
8 | 4116 |
9 | 19108 |
10 | 89926 |
11 | 427386 |
12 | 2068934 |
13 | 10163358 |
14 | 50888024 |
15 | 258983668 |
16 | 1342912608 |
17 | 7079970072 |
18 | 38000183102 |
19 | 207309599246 |
20 | 1150329076074 |
21 | 6484351459090 |
22 | 37143321514076 |
23 | 216001121263896 |
24 | 1275332898098744 |
25 | 7639400455469944 |
26 | 46423461664822648 |
[0,0,1,7,39,188,884,4116,19108,89926,427386, 2068934,10163358,50888024,258983668,1342912608, 7079970072,38000183102,207309599246,1150329076074, 6484351459090,37143321514076,216001121263896, 1275332898098744,7639400455469944, 46423461664822648] |