n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 2 |
3 | 6 |
4 | 14 |
5 | 38 |
6 | 124 |
7 | 400 |
8 | 1232 |
9 | 3712 |
10 | 11288 |
11 | 34628 |
12 | 106352 |
13 | 325772 |
14 | 996712 |
15 | 3050352 |
16 | 9340170 |
17 | 28602014 |
18 | 87576426 |
19 | 268129662 |
20 | 820931640 |
21 | 2513509536 |
22 | 7695861408 |
23 | 23563048304 |
24 | 72144604576 |
25 | 220890113784 |
26 | 676315440208 |
27 | 2070725515096 |
[0,0,2,6,14,38,124,400,1232,3712,11288,34628, 106352,325772,996712,3050352,9340170,28602014, 87576426,268129662,820931640,2513509536, 7695861408,23563048304,72144604576,220890113784, 676315440208,2070725515096] |