n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 1 |
3 | 4 |
4 | 14 |
5 | 44 |
6 | 131 |
7 | 376 |
8 | 1052 |
9 | 2888 |
10 | 7813 |
11 | 20892 |
12 | 55338 |
13 | 145428 |
14 | 379655 |
15 | 985520 |
16 | 2545720 |
17 | 6547792 |
18 | 16777993 |
19 | 42847988 |
20 | 109099078 |
21 | 277040572 |
22 | 701794187 |
23 | 1773851304 |
24 | 4474555476 |
25 | 11266301976 |
26 | 28318897549 |
27 | 71070913036 |
28 | 178106093666 |
29 | 445740656420 |
30 | 1114147888655 |
[0,0,1,4,14,44,131,376,1052,2888,7813,20892,55338, 145428,379655,985520,2545720,6547792,16777993, 42847988,109099078,277040572,701794187,1773851304, 4474555476,11266301976,28318897549,71070913036, 178106093666,445740656420,1114147888655] |