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n·2n (n-1)·2n-1-1 (n-1)·2n+1 2n+1
H5N1、H7N7 H5N1、H3N2 H3N2、H7N7 H9N2、H3N1 H3N2、H3N1
an=2n2+3n-1 an=n2+5n-5 an=2n3-3n2+3n-1 an=2n3-n2+n-2
|N1|=|N2|;|N3|=|N4| |N1|>|N2|;|N3|>|N4| |N2|<|N3|;|N3|<|N4| |N1|>|N2|;|N3|<|N4|
n1>n2>n3 n3>n2>n1 n2>n1>n3
N1<N2<N3=N4 N2=N1>N3=N4 N1>N2>N3=N4 N2>N1>N3=N4
N1=N2=N3 N1≠N2≠N3 N1=N3>N2 N1=N3
N1=N2=N3 N1≠N2≠N3 N1=N3>N2 N1=N3<N2
m=1,n=3 m=1,n=-3 m=-1,n=-3 m=-1,n=3
n+(n+1)+(n+2)+…+(2n-1)=n2 n+(n+1)+(n+2)+…+(2n-1)=(2n-1)2 n+(n+1)+(n+2)+…+(3n-2)=(2n-1)2 n+(n+1)+(n+2)+…+(3n-1)=(2n-1)2
0 1 2 1 2 3 2 3 4 3 4 5 4 5 6 5 6 7 1 3 5 3 5 7 5 7 9 2 4 6 4 6 8 6 8 10